Forced to drive through light salt today, issues? [Archive] (2024)

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TylerWeslow

13th April 2020, 23:01

In Green Bay we got a bit of a snowstorm last night, and unfortunately the salt trucks were out. Perfect timing as my car was at a shop in town for an alignment, and I had no choice but to pick it up and drive it home. By the time I left to pick the car up, the roads were completely dry, but I noticed closer to my house in the country the roads still had some dry salt on them. No big chunks, the roads were just slightly stained white from the brine they put down.

I was sort of freaking out on the inside because my car has only been summer driven and never seen salt. I flushed out the fender wells, bottom of the rockers and (as best I could with the car on the ground) underbody.

Bocoloco

13th April 2020, 23:31

If I were feeling really OCD and guilty about the salt, id put the car up on jack stands, disconnect the battery for ghits and shiggles. Wait for it to be nice and cool then use a mixture of purple power/ simple green and a scrub brush and literally scrub clean and rinse repeat absolutely everything on the underside of the car. lol

Take it i would only do this on that dream 16k mile creampuff ive yet to find in some garage in Ontario.

Anyhow i wouldn't worry too much sounds like you rinsed all the salt off when you got home.

MK1888

14th April 2020, 06:20

Salt is more of a repeated exposure problem, not a one time thing. You don't get cancer from smoking one time.

cduplain

14th April 2020, 06:22

That sucks. I would have done what you did.

ElmerFud

14th April 2020, 06:25

Go and buy 4 cans of Fluid Film from Lowes and spray liberally the whole undercarriage. It will help prevent or slow down any rust. I'm a daily driver too and do this every winter. You can also buy an attachment with a hose extension to spray in those nooks and crannies and frame rails. This is my humble opinion, no I don't have facts or fancy charts, your mileage may vary, no need to flame.

3MiataFamily

14th April 2020, 07:54

Spray the underside...let dry..take two shots of bourbon and relax

Bob_MX5

14th April 2020, 11:21

Good advice above except #3. :eek:

Undercarriage rust, like cancer, forms over time. Do nothing and yesterday was day 1 of salty undercarriage. Today is day 2. Tomorrow day 3...see where I'm going with this. :thumbs:

KimE

14th April 2020, 11:28

Spray the underside...let dry..take two shots of bourbon and relax

Could you make mine a Manhattan with ta-hooo cherries please.

New Yorker

14th April 2020, 12:13

Am I freaking out for no reason? The drive is maybe 15 minutes, and thankfully none of the roads were wet with brine. Should I somehow get into the rockers and flush them out, or just wash it good the next time it's nice out and not worry?
Yes, you most definitely are freaking out for no reason. Youre acting as if your Miata has no rust protection whatsoever. But it does. Certainly enough to withstand an occasional trip on salt covered roads. And especially if you washed the lower parts of the car afterwards, as you clearly did.

So relax! You have absolutely nothing to worry about. Really!

Need4Speed

14th April 2020, 12:32

Can you post the VIN? We want to flag it so any future buyers know of this. [emoji6]

3MiataFamily

14th April 2020, 12:35

MK1888

14th April 2020, 12:46

Good advice above except #3. :eek:

Salt *is* a repeated exposure problem, not a one-time deal killer. He had one exposure and he cleaned it. Not a big deal. Lighten up, Francis.

Houleo

14th April 2020, 12:56

Do this once a year, take care of the body and it will last as long as the motor/transmission/diff with regular fluid changes. Look for and address areas where the undercoating has worn away or is compromised, remove the plastic cover behind the seats, near the door opening and there is an opening where you can access the back of the rockers/front of the quarter panels and spray coat it with FF, frame rails too.

houleo -> steps off soap box

TylerWeslow

14th April 2020, 13:40

Can you post the VIN? We want to flag it so any future buyers know of this. [emoji6]
I'll make double sure to mention it to my future buyer, rest assured.;)
Spray the underside...let dry..take two shots of bourbon and relax
Yes, you most definitely are freaking out for no reason. Youre acting as if your Miata has no rust protection whatsoever. But it does. Certainly enough to withstand an occasional trip on salt covered roads. And especially if you washed the lower parts of the car afterwards, as you clearly did.

So relax! You have absolutely nothing to worry about. Really!

To the OP...I just did a little digging..you are not the original owner so you have no 100% assurance that your 97 had never been on a salty road in its history....you are definitely overthinking this...
This is very true. The car has been in the midwest for over 10 years now I believe, so odds are it has seen a salty road or two before. Very good point.
Salt *is* a repeated exposure problem, not a one-time deal killer. He had one exposure and he cleaned it. Not a big deal. Lighten up, Francis.

You all really put my mind at ease. I guess just seeing all the rusted out Miatas up here in the midwest freaks a guy out a bit. I actually used Fluid Film on my Mazdaspeed3 I drive in winter, and it worked wonderfully. Maybe I'll spray some up in the vulnerable areas once it gets nicer out as a future precautionary measure in case I need to drive it in salt again sometime.

Thanks again everyone - I think I'll take your advice and pour myself a drink. ;) Cheers!

arathol

14th April 2020, 13:48

Salt *is* a repeated exposure problem, not a one-time deal killer. He had one exposure and he cleaned it. Not a big deal. Lighten up, Francis.
Wrong, no, incorrect...Salt is not a "long term exposure" issue. If you drive your car on a salt covered road just once, and that salt gets all over the underside and into the fender pockets and all the places you don't normally clean that well, it will rust in time. It doesn't take much salt to start the corrosion either. When you wash the car, salt will dissolve into the water and can be carried and deposited in small amounts into every tiny crack and crevice. All those tiny bits of moisture that remain after you wash can contain salt residue. Just because you wash with soap and water doesn't mean you get it all. Residue will remain, and it will eventually start to rust. If you want to make sure you get all the salt residue off and and prevent corrosion, you need to use a chloride neutralizer such as Neutrowash.

Driving on roads covered with dry salt residue is worse than wet roads. Salt is aerosolized by traffic, and the dust can get into everything, inside and out. It gets drawn into the air vents, it gets into the electrics, etc. This is especially bad when the sodium chloride road salt is augmented with other de-icers like magnesium chloride.

Bocoloco

14th April 2020, 14:10

Wrong, no, incorrect...Salt is not a "long term exposure" issue. If you drive your car on a salt covered road just once, and that salt gets all over the underside and into the fender pockets and all the places you don't normally clean that well, it will rust in time. It doesn't take much salt to start the corrosion either. When you wash the car, salt will dissolve into the water and can be carried and deposited in small amounts into every tiny crack and crevice. All those tiny bits of moisture that remain after you wash can contain salt residue. Just because you wash with soap and water doesn't mean you get it all. Residue will remain, and it will eventually start to rust. If you want to make sure you get all the salt residue off and and prevent corrosion, you need to use a chloride neutralizer such as Neutrowash.

I agree that any exposure to road salt will inevitably lead to future rust, but unless the OP drove in the salt every weekend for the next year and put the car away wet I think it would take 20 something years to see the end results of one drive on a lightly salted road.

Your just worrying the OP for no reason lol Hes good evan rinsed it after words. Also again thats why i would only express extreme concern on the unicorn one owner 16k mile car. Anything other then that is just driving yourself crazy. Madness

arathol

14th April 2020, 14:56

And you would be wrong. I dealt with salt corrosion issues on vehicles for many years at work on a professional basis, and believe me all it takes is one time and a couple weeks for it to start if you don't get it cleaned properly and neutralized. Salt is slow acting and very invasive. All it takes is a small bit in the rockers and in time there will be holes, especially with the newer MgCL2 de-icers.....that stuff eats cars for lunch. Unfortunate, but true.

Bob_MX5

14th April 2020, 15:12

Salt *is* a repeated exposure problem, not a one-time deal killer. He had one exposure and he cleaned it. Not a big deal. Lighten up, Francis.

Then nature of salt spray is that it gets every where in the undercarriage. Once you have a layer of salt, it's there until you remove it. Corrosion begins on the first exposure, not the second, third or forth and it worsens over time. Certainly, the damage worsens quicker with multiple exposures but to think it won't start with just one exposure is reckless and just plain incorrect.

Flushing out the wheel wells is a good start, and it was a smart move on the part of the OP, but not enough to truly mitigate new or previous corrosion.
For example, please take a look at the photo's of the 93LE being discussed in P&DD and being offered at $14.5k. Yes, its had multiple exposure and the level of corrosion/rust it is significant; but look at the extent of coverage. It's every effing where because of the nature of spray!

Also remember, the OP is not the original owner. This is his first time of exposing his Miata to salt. Very doubtful (although certainly possible) that this is the historical "First" time for his Miata.

Regards,

Francis.

3MiataFamily

14th April 2020, 15:18

you want rust?...it took 254k as a DD in PA and another 60K in CT..and 18 years.. to get to this point...it is an NB, which has a totally different issue in the front unibody area...but when I scrapped it at 317K...this is the major reason...in addition to a couple broken fingers on the pressure plate...engine/trans lives on in my 99

ElmerFud

14th April 2020, 18:11

This is encouraging, did you do any preventive measures along the way?

SteveNA

14th April 2020, 18:32

Tyler, believe me, I live in Ohio so I know rust caused by winter road salt. Your one little drive over some dry salt is not going to hurt anything. Some of these guys have been in the house a little too long. There are things you can do to help prevent future rust like sealing up the gaps where the rear quarter panel is spot welded to the inner wheel house, and blowing wax oil into the lower front quarter panels and other box sections, cleaning out the lower fender areas, etc. etc , but this is a totally different topic that you might want to do some searches on. If you aren't driving the thing in the winter and keeping it out of much rain you are likely going to be ok for many years.

MK1888

14th April 2020, 18:48

Also, some of these guys *aren't* from the Rust Belt.

MK1888

14th April 2020, 18:52

I guess just seeing all the rusted out Miatas up here in the midwest freaks a guy out a bit.

That's because most previous owners don't clean under their cars. They're exposing their cars to salt all winter long, for years, with at most one car wash in the winter, and are only concerned about the top side.

3MiataFamily

14th April 2020, 18:55

This is encouraging, did you do any preventive measures along the way?

I bought it 'pre-rusted'...just too good a deal to,pass up...another 60k on hat chassis and the engine/trans still lives on

gtxhawaii

14th April 2020, 19:14

The real problems are the exact chemicals involved. Unfortunately this is a poor time to get responsive answers from local functionaries as to the mix of salts used on your roads. Try anyway, how it matters later on.
A comprehensive set of countermeasures would be advised if the car is truly valued. Initial rinse with tap water is obvious. Using a wand to put significant amount and pressure to dislodge all the salts dust possible is next. If the roads are now Clean, an Italian tuneup offers good wind velocity that few, or no, other methods do, to move and dry water. Attention to the particular shortcomings of the Miata chassis are next. Liberally douching the front fender dirt collecting areas at the lower rear might be addressed by flushing both sides of the cowl space used as a cabin air intake. Both sides dump to the enclosed volume between fender and chassis. If this work evidences any dirt, mud or vegetable debris, move to unscrewing the lower rear of the fender and Thoroughly rinsing it. The above spray might be considered, but I don't think flushing work is finished yet.
The rocker panels are next. Close inspection of the seam midway up the rear wheel well may or may not be well sealed, depending on parts fit and maybe the attitude of the factory worker that car. Flush anyway, and note for sealing later. The main water channel feeding the rockers seems to be the rain rail drains on each side. Don't take my memory of earlier discussions as fact! Investigate!! Help from more chassis experienced workers here should be sought, in bold, italics, PMs, and anything else you can imagine. The water or whatever that gets into the spot welded seam between major chassis unibody components feeds into the rear of the rocker panel, and out the 2 drains at each jacking point. The rocker panel also opens to the front, taking water from the space outside the footwell sidewall. Which is a low wall, and accessible if the plastic footwall panel is removed. I propose that with care and experiments, the general rocker panel can at least be flushed, possibly flooded well above normal rain or car washing water lines, for much more thorough flushing, and then salt neutralization. Which is the step after what flushing was done by water, is dried as best possible. The final rinse needs to be an efficient mix of neutralizing chemicals, to as best possible, remove any salts. This matters as moisture is absolutely certain to reactivate any salts left in proximity of exposed metals. Which is totally predictable at most stress locations of the chassis as paint ages and metal fatigues. Rain is Not the problem! It's the humidity of air in most of the country. Even the dry desert basins of the West and Southwest have high humidity times of year, often extended when repetitive fronts keep moving over from different directions. And even in 'dry' season if the common over development of cumulonimbus super cells is encouraged. Where 'dry' season gully washers originate. The only real alternative is a dry nitrogen bubble enclosure, as is now the practice with some multi-million dollar valued classics approaching 100 years old, if not there already.
Once a suitable neutralizing solution is sourced, possibly the Neutrawash discussed above, the whole rinse and hidden crevice exercise with hose, wand, or whatever tool is helpful, is repeated. Having been done lately, it goes much faster, particularly if all disassembly has been practical to leave in it's accessible state.
Research may validate the claims above about Fluid Film. Whatever that outcome, the best available, to your research limits, is applied again, to all accessible, or just hoped for access, metal on the chassis. You'll certainly know your Miata far better at the end, and it just has to last longer. Given the chassis metallurgy chosen, and the paint technology of the 1990s, not an immortal car. Current budget strapped road maintenance practices hardly help, both the salting, and the impact stresses damaging paint and fatiguing metal from rough and potholed pavement.
You may want to intersperse in the process one of the 'hole and spray' commercial chassis rust preventing metal coverage treatments. My readings are that the best are not drying, but stay at gooey surface that has both hydrophobic/water exclusion properties, and some long term self-healing over widening or new cracks in covered paint. Some may be wax based, others more high molecule weight oils, greases or other hydrocarbons. The strategically located new access holes may greatly increase treated area. Mazda's choices designing the rocker panels and other structures prevents any total coverage, or even rinse and neutralization, unless some creative dip can be arranged. The chassis was originally base painted by a 'in the metal' (Bare welded up metal chassis, no parts attached) paint pool dip, if similar to other platforms' practice of the era.

All the "It's OK!" posts neglect one basic fact. The car is several distributions out from the mean peak curve of known NA Miata condition now, as good of car simply is raw luck to Ever find, and hideously expensive and cost skyrocketing in an increasing curve to the future. Simply, there aren't any more new ones. If you want a Miata, that is serviceable into more than the immediate future, you pretty much have to preserve what you have. Some of us have cars that may outlive us. But as many nice Miatas may already be as old as their owners, and more will be every year. They were NOT engineered nor constructed to last much over a decade.

Whatever the process of remediation, if any, the anxiety of this episode might encourage a far more serious negotiation with shop or property owners in similar situations as to when the car has to be picked up? Betcha wish you had a 'Do Over' button?

New Yorker

14th April 2020, 19:48

^ Or just drive it.

Bob_MX5

14th April 2020, 20:20

Also, some of these guys *aren't* from the Rust Belt.

Right, because in America nobody ever moves. :ohno:

o1marc

14th April 2020, 20:54

Build a car and go to Bonneville and you will come home with a new education on salt effects. On one run in the Metro the second piece of the belly pan front edge came undone and turned into a salt plow at 240mph. Took 2 hours to clean the salt out of the engine bay. At the end of a season of maybe 4-5 events, it's surprising how much damage the salt has already done. And that's after a thorough cleaning after coming home from each event. We build show quality race cars and they look like crap after one season.

cduplain

14th April 2020, 21:20

The range of responses in this thread is absurd. OP, here is what I would like you to do.

1. Take pictures of your undercarriage and rocker panels. Post them here.

2. Once the roads are clean, rinse your undercarriage and rocker panels really well (no disassembly of anything) and immediately go for a nice drive to air dry everything. Repeat that two or three times over the next week or so.

3. Avoid driving your car in the snow or salt for the next five years.

4. In five years, take more pictures of your undercarriage and rocker panels. Post them here so we can compare.

This is the only way to see who in this thread is right. I am being 100% honest when I request this of you. We have all seen those Miatas with rusty undercarriages and an owner swearing it was never driven in the snow or salt. I have often wondered (and asked on this forum) how many trips on a salty road it takes for significant rust to form. Is a good rinse (or three) enough to prevent significant damage in a case like this? I think so. But, for the sake of science, do it!!!

arathol

14th April 2020, 21:27

Also, some of these guys *aren't* from the Rust Belt.
Whats your version of the rust belt? There is plenty of salt on the roads here in CT. We use NaCL, with CaCL and MGCL2 added to increase effectiveness below freezing. I've spread thousands of tons and thousands of gallons on the roads here over the past 30 years, and thats just one truck. The department fleet has 630 trucks and a couple hundred contractors, and thats not counting the towns and cities with their own fleets....Every department has salt corrosion issues that need to be dealt with on a daily basis in the winter. It only takes a few days for the salt mixes to do damage if the equipment is not washed and neutralized after a storm. You can wash with soap all you want, you will have salt residue left. A good chloride neutralizer is needed to get rid of that residue in order to prevent corrosion.

SteveNA

14th April 2020, 21:48

The car has 68K on the odo and whether it was driven in some dry salt or rain over its life there will be some unplaited nuts and bolts and brackets underneath that will have surface rust and that doesn't hurt anything. I sold an NA last summer that I bought with 26k on it and added another 10k, I never drove it in the snow and the original owner said he didn't either. Whether he did or not it still had surface rust on some brackets and nuts and bolts that were not plaited or well painted. So what? It hurts nothing. It's when the slurry runs between the spot welds in the rear wheel arch and runs into the lower quarter panel and does the typical rust perforation that you have a problem. That isn't at issue here.

cduplain

14th April 2020, 21:54

You can wash with soap all you want, you will have salt residue left. A good chloride neutralizer is needed to get rid of that residue in order to prevent corrosion.

Ok...neophyte question here. If salt residue cannot be removed with soap and water (or just water), then why is it washed off of the roads and the exterior body panels of cars after several hard rains? The roads aren't cleaned with chloride neutralizers. If it is truly impossible to remove with just water, then it would never, ever be safe to drive our cars on the roads after they have been salted. Ever. No matter how many times rain water rinses them clean. So, are we screwed no matter what?

TylerWeslow

14th April 2020, 22:11

I feel like I'm safe due to the fact that it was completely dry, and no snow slurry/water was present to squeeze its way into the nooks and crannys of the car.. but some of you definitely got me still worried. To be safe, I ordered some Salt Away and will be flushing things out best I can. If anyone has some tips on getting into the rockers to flush them out, let me know. I found some posts about removing the kick plates and getting in from there, but I feel like the holes are too small. I guess we'll see. I appreciate all the feedback from everyone!!

arathol

15th April 2020, 01:21

Well, the roads retain salt much longer than you would think. The visible gross particulate is washed away, but residue stays for a long time in the tiny cracks and fissures in the pavement. This residue retains moisture and in colder temperatures causes extended freeze/thaw cycles, which is how pavement damage occurs, but that a different matter entirely.
As for cars, its quite difficult to remove 100% of the residue. You can wash it off the exterior body paint because the paint is sealed and impervious to penetration. The underside of your car, not so much. Any painted surfaces there are probably compromised within days or weeks from being new just from sand and other stuff coming off the road, and so they are vulnerable to corrosion. You can wash the visible stuff off, but still you'll have residue in places you can't see. The surface of any untreated steel has tiny micropores and imperfections, it isn't perfectly smooth. This is where the salt hides, and once it takes hold it will cause corrosion. Its generally not the big visible stuff that causes corrosion, but rather all the tiny bits that hide in every crack and crevice.

gtxhawaii

15th April 2020, 03:11

I'm totally with arathol on this one. Besides understanding the chemistry and movements of microparticles, living for 50 years in what is in ways a higher salt environment than snow belt salted roads. Near the coast along onshore parts of the islands, constant trade winds bring salt water particles in year long. On the large surf areas, less often when mild onshores combine with apartment building high waves, but heavier loadings. We can scrape the salt off before morning drives with ice scrapers. And have to if we want visibility through the glass. Actually, just a hose works, but you can easily empty the windshield washer reservoir in a few days. The salt burn that kills or removes most foliage from plants is why few try to farm salt laden coast land.
The chemistry of ferrous metals and family of halogens is intense. The whole family of halogens, chlorine is second in activity after fluorine, is named after its strong characteristic, to 'make salts', a rough translation of "halogen". Such eager chemicals Are going to react if in electrical contact with iron chemicals, same as putting a group of teen age hotties together. There Will be intimate relations.
Well sealed ferrous metals aren't in contact with salts. Our Miatas came before one of the Korean disrupted the traditional car construction process by offering 10 year rust out warranties. Everyone had to react. The latest cars are marvels of factory rust resistance. Till the paint is scratched over ferrous panels
. Our Miatas have not-well-designed for corrosion longevity structures, that flex in stress areas more than the paint flexibility or adhesion can sustain. Micro to visible cracks are everywhere that forces flex the metal repeatedly. I'm on my third Miata with rust perforation in the A-pillar just above the top door hinges.Zero damage, other than the door flexing the metal, and exceeding the paint's ability to retain a seal.
Salt particles aren't all visible, potent chemicals are in the aerosols that simply go everywhere there is a gas filled passageway, or in liquid water that is allowed to penetrate. No matter how small, exposed metal will react to chloride salts, and the process is started, usually out of sight, and unfortunately, out of access to clean or repair on several parts of a Miata.
Do what you can now, repeat any flush and salt treatment followed by an Italian tuneup as soon as the roads are fully washed and sun dried. The highway speed air has penetration properties few machines can match. Assuring the few drain points on the rocker panel are well opened, and the paint refreshed where any opening tool just has to damage the covering sealant, is the least an ambitions owner might do.

As pointed out, visible dry salt will be pounded by traffic to microscopic and larger particles. Same as horse droppings. Why the cities of the horse and buggy days were so toxic for lung infections like the 'consumption', now called tuberculosis, that fills so many period biographies, their version of our respiratory disease.

SteveNA

15th April 2020, 06:59

Tyler, the rockers are not your problem, firstly they are waxoiled from the factory, shine a light in there from the holes under the sill plates and you can see. How did dry salt get into them, through the drain holes? Certainly not. In fact, from the little bit of dry exposure you had, you don't have a problem at all. The rockers don't rust anyway, not until the lower quarter panel is so far gone that water gets into them from an exterior hole.

Mazda23Miata

15th April 2020, 07:07

I am a retired mechanic and I do live in the rust belt, upstate NY. I agree with all those who say any exposure is too much and will initiate corrosion. The spry and mist created by your own car and those around permeates every possible crevice of the structure. Most of those places are impossible to clean. All one needs to do is remove a few fuel tanks, engine cradels or look inside a door to see how much accumulates in even relatively easy places to flush. Most corrosion is galvanic in nature. All you need is dissimilar metals and an electrolyte. Salt water is thee electrolyte. I remember our discussions at work when during the winter we would get one of those rare days when the road was dry and the temp. was perhaps 60. Specialty cars and motorcycles could be seen driving about. We would cringe and wonder if the owners had any idea of the damage they were doing. Road was dry but covered with salt powder. Again that dust would permeate the entire structure, all that was needed after that was a humid day and condensation. When cutting away panels for extensive body work many of these hidden places are exposed and what looked rust free on the surface was not. Now if we assume the op's car was never exposed before this current encounter is he going to find extensive visible rust 18 months from now? Of course not but that does not mean the salt had no effect. I do not drive any of my summer cars or my motorcycles until we have had at least one long hard spring rain. For any who want to truly understand corrosion and the ways to mitigate its effects I would highly recommend buying an aircraft corrosion publication. They cover theory, will provide a chart of the nobility of metals and describe various methods to prevent corrosion. These are very detailed explanations as corrosion in aircraft is not only a cosmetic issue but a mater of life and death.

Mazda23Miata

15th April 2020, 07:23

All through my career I would hear people say I never----had the valves adjusted-----performed a proper storage procedure----- changed brake fluid------ changed oil at recommended intervals - and I never had a problem. What they are really saying without knowing the distinction is that they never had a failure. I have had to repair issues countless times that were the result of this approach. Unfortunately the problems often take months or years to surface and I learned to not even try to explain to the customer that their lack of maintenance led to the problem. I wonder how many of those saying one time in the salt will have absolutely no effect have actually done extensive auto disassembly and cut away body panels.

gtxhawaii

15th April 2020, 08:37

. . . The rockers don't rust anyway, not until the lower quarter panel is so far gone that water gets into them from an exterior hole.
This just can't be let stand. Rockers are where the most distructive of rust starts, the frequent holes where substantial interior rust finally erupts through the surface when metal turns to bubbles under the paint. Normally when the interior is exposed, the complicated stress structure under the cosmetic rocker cover has been attacked badly. The rocker drain holes exist Because Mazda designed the rocker as a deliberate drain from above, not some afterthought ventilation. All the salt and 'other' from above ends in the rockers, and stays if too big to pass through the small holes. Mazda even released a tech paper (seen in Garage, IIRC) on enlarging the drain holes to prevent even earlier rust if the water and whatever, couldn't drain.
If any 'waxoil' actually worked, a lot more people's Miatas wouldn't have gone to the crusher.

SteveNA

15th April 2020, 11:53

GTX with all due respect, you don't know the construction of the lower part of a Miata nor do most. This has been discussed many times with cut away photos, etc. showing repairs and on and on.
Please read this: The rocker panel runs from the rear of the front wheel arch to the front of the rear wheel arch, and stiffens this part of the body. You only see the part of it under the door. The lower front fender covers the front of the rocker and is bolted to it with 3, 10 mm bolts as I recall. The rear quarter panel covers the rear portion of the rocker panel and is spot welded to it. That seam that you see in the rocker below the rear edge of door is the start of the quarter panel. The rear quarter panel is spot welded along the bottom edge just before the rocker turns in and than drops vertically. It is not the rocker panel rusting through in front of the rear wheel arch, it is the lower quarter panel because salty dirty water seeps from above where it gets between the spot welds holding the quarter panel to the inner wheel arch. There are gaps between those spot welds and the corrosive liquid seeps in and runs down BETWEEN the rocker panel and quarter panel. Those drains that everyone talks about do not drain this sandwich of two panels welded together. The photo I have posted shows the lower rusty quarter panel cut away leaving the actual rocker panel with the two large holes. That is just a continuation of the black area that you see under the door. It is one panel from front to rear, you only see what is under the door. If the lower rear quarter panel rust is bad enough, over time more water will seep in from outside and start rusting the section of the rocker panel under the door, but this is not where the rust starts first, it starts in the lower quarter panel as explained above. This can be prevented, but I'm not going into that now. In any case the little bit of dry salt the OP drove over is not going to hurt anything.

Sporin

15th April 2020, 12:24

This thread makes me glad my car is a well-used driver, and not a showroom piece. Zero body rust but the underside has enough orange on the steel parts that some of you all would probably scrap it. :D For me, here in Vermont, it's more than clean enough for years and years more of happy summer use.

You can buy a brand new vehicle here, in the middle of summer, and it will have rust on some parts underneath. That's the nature of metal and air, let alone airborne contaminants, salt, etc.

TylerWeslow

15th April 2020, 12:47

You can buy a brand new vehicle here, in the middle of summer, and it will have rust on some parts underneath. That's the nature of metal and air, let alone airborne contaminants, salt, etc.

Honestly Im kinda at this point.. my car is far from perfect, its not stock.. I guess I dont know why Im worrying so much. The car is driver, with low-ish miles.. I suppose I just wanted to keep it as clean as possible. Im just going to spray it down with some salt away and forget about it. Its spring time, I should be enjoying the car instead of worrying about some possible rust thatll most likely come years from now.

MK1888

15th April 2020, 17:19

Yep. I don't wanna be 90, too old to drive (although my mother still drives at 90) and say "I wish I had spent less time driving and more timing polishing/admiring that fun car I had."

gtxhawaii

16th April 2020, 06:21

I'm well aware of the exterior rocker panel configuration, and the load bearing complexity behind. If it's been discussed here, I've seen it. My opinions on the exposure of all this metal to major and incidental environmental exposure stands. What rinsing or salt neutralizing that is possible in the general area, or above in the designed 'watersheds', also moves debris and salt into the lower areas that are inaccessible without a destructive disassembly to access, as that's were the 4 drain holes in each rocker drain from.
Yes, one brief exposure doesn't doom the car to fall apart immediately. But in any given number of years, it's effects would be noticeable versus an identical car which had Not been driven on dry but salted roads. My experience with Miata chassis in a high salt environment showing in great detail where all the vulnerable places are, gives great skepticism even a full-press cleaning (on an assembled Miata) completely neutralizes the dangers of driving over salt, dry or wet. Damage and risk are proportional to exposure. NO exposure is better than any above that.
One has to realize that atmospheric humidity will get the car eventually, as the paint is not as strong or attached well enough to survive a number of stresses, most important to hidden chassis locations, metal flexing more and more over the years as fatigue takes it's toll. Surface paint damage is amenable to spot fixes.
Where I'm seeing little or never discussed full panel perforation and 'ulceration' expanding, are high stress areas above the top door hinge welds, under the complex parts corners at the windshield base. My impression is this starts inside the cabin by the ends of the dash, and moves out along spot welded seams to the exterior, all vulnerable due to chassis loadings and stress flex.

ElmerFud

16th April 2020, 06:49

Unless your in a controlled temperature environment like say a museum there will always be some form of rust forming. That's why I recommend Fluid Film with a long tube attachment, because the thin nozzle multidirectional tip on the 3 ft long wand fits easily through those small holes. Will it totally prevent rust from forming, No, but it helps to slow it down so you can drive your Miata till your dead or sell it!

And no, I do not work for Fluid Film or have stock in them, just happened to use and love their product. Just joking here, but in southern Virginia we probably put down more salt additives on our roads during a light snow dusting than all you northerners put down all winter long! :rofl:

SteveNA

16th April 2020, 10:02

Not to belabor this, but the drain holes you speak of in the rocker panels do not drain the area where the lower quarter panel is sandwiched and spot welded to the outer rocker and this is where the corrosive crap ends up that causes the thin lower quarters to rust through. Those drain holes drain the insides of the box shaped rocker panels, and that is fine but it doesn't prevent the lower quarter panel rust though no matter how many times people say it does. You want to prevent lower quarter panel rust through, caulk up the gaps between the spot welds around the rear wheel arch and spray waxoil or whatever you like from above into the area in front of the rear wheel and there are a number of ways to do this.

ElmerFud

16th April 2020, 12:04

I'm a retarded Miata owner myself, but that makes a lot of sense! ^^^

SteveNA

16th April 2020, 12:40

I'm a retarded Miata owner myself, but that makes a lot of sense! ^^^

Not at all Elmer and any waxy rust resistant product you could inject in that space will be helpful. I have made my own from time to time; dissolve a wax toilet seal into mineral spirits and add a dash of thin unused motor oil, works fine..... Photo attached shows where this can be injected, upper photo is small hole I drilled, lower hole shows existing found after removing plastic shield. If not much rust has formed between the outside of the rocker and the inner quarter panel where they are spot welded together, this stuff will actually seep out between the two at the bottom where the quarter panel ends.

Mazda23Miata

16th April 2020, 19:33

What we have here to a great extent is the difference between theoretical and practicable. Due to nature and physics our cars start to rust the moment they are created. Protected from outside corrosion accelerators that rust is completely insignificant and the car has the potential to last for centuries. However each time we expose the structure to those accelerators we shorten the life of the structure. But this is not an all or nothing situation. Will one exposure to salt accelerate corrosion? Yes it will. Will that one exposure be enough for the average owner to notice the effects? probably not. Look at all the photos of low mileage miatas on ebay. Notice how many have corrosion on the cam cover. The cam cover is aluminum, yet there is clearly something going on. What we see is aluminum oxide, aluminum's equivalent of rust. One simply can not stop all rust but what we can do is greatly slow it's production by eliminating accelerators. A friend of mine had a Mini Cooper for 13 years. She drove that car year round in upstate NY. She believes at the time she sold it that it was rust free. Any experienced mechanic working in the rust belt could safely bet their life that the car was not rust free. However an external walk around would lead one to believe it was rust free. Nature is relentless and our cars will rust.

Bocoloco

16th April 2020, 20:22

Again, i understand the aforementioned affects of rust. Im not a rust scientist i probally should not evan have room to argue here. But this is a great discussion here, luckily in Nor Cal rust like you guys in the salt belt there is hard to find here. Evan cars from the 60's 70's stored outside all their life havn't rusted that bad. Ive got a 74 camaro with lots of surface rust but its still nice and solid. And interesting debate/ comparison is different metals from different periods of time and production (from different places in the world), and how their rust formation differed from other metals based on where they were manufactured and how.

Mazda23Miata

17th April 2020, 11:01

10or 12 years ago I purchased a Neon ACR from Riverside CA. Had it shipped to my upstate NY address. What a treat, I would schedule myself blocks of time to work on the car. But in each case my estimates were extremely pessimistic. I have a lifetime of struggling with rust. Even the exhaust manifold bolts on the Neon once broken loose spun off with my fingers. At work we had several 6 ft high bins filled with fasteners. Many times the most efficient repair was to take an air wrench and just break off the fastener. Air brakes seized. electric brakes failed due to wires rusting off, we had to condemn vehicles that looked fine externally due to structural rust. Pintal hooks seized, parking brake cables seized, trailer fenders rusted thru. Even bucket truck turrets and supporting structure rusted to the point they were not safe. We has a Freightliner tech adviser who lived in Ohio and traveled a good part of the country, he commented that he did not believe they could ever produce a product that could survive our local conditions. When I purchased my Miata from a local import dealer the salesman told me they had gone to DPW and obtained a jar of the what was being used as ice melt because the manufacturer simply could not understand why they were having rust issues. I had to condemn a van that only had about 60k miles because though the body looked perfect the idler arm frame support was rusted to the point of potential failure. A co worker had a late model Patriot, again exterior looked flawless but you could literally put you entire hand thru the hole in the engine cradle. Rust sucks.

MK1888

18th April 2020, 13:24

This just can't be let stand. Rockers are where the most distructive of rust starts

GTX, have a look at this video, starting at 5:26.

https://www.youtube.com/watch?v=wVWl3ynXlJk

You'll see that the rust is on the outside of the rocker panel, between the rocker and quarter panels. It doesn't appear to be related to the factory drain holes.