Technical Another Paint Failure 35 Buick

So last week I had a shop call me, they have a 35 Buick a customer brought in that had paint coming off with no effort at all, they didn't originally do the work. The owner has had 3 other shops do repairs with no luck. So I went there and found 2 separate issues. The first issue was ospho applied incorrectly, paint will just come off with no effort (see picture in the first picture in the cardboard box is nothing but flaked off paint.

The other issue was who ever painted the car forgot to tack the car off before applying paint. Paint doesn't stick to dust too well. Now I didn't know this until the underside of the paint was examined under a microscope. If the shop would have skipped the ospho all together and went with straight epoxy, and tacked the car off there would have been no issue.

So the reason I am posting sometimes not over thinking a paint project and going with a tried and true method of Epoxy on fresh bare metal, and always keeping your surface area clean will result in cleaner more durable finish.

And in case you are wondering, yes the whole car has to be stripped! And yes you bet your ass epoxy is going on next.

I will keep you posted with pictures, this will not take long.

 

Hate to ask but "ospho"? I assume its a type of metal prep to prevent rust ?
Im tryin to learn about all this stuff.

 

I'm guessing phosphoric acid. But then there is http://www.ospho.com/

 

Yes its a acid etch.

 

I didn't think ospho was an acid etch but a rust converter. I don't think it does anything on bare, unrusted metal.

 

Thanks for posting

 

One thing I've learned about refinishing. Do it right. Do it right every time,.....and maybe it will turn out right.
With the Internet and all the opinions of the best way to do something, I like what you said
" tried and true". Thanks for making people aware. I've considered using OSPHO after reading others comments,but went with epoxy and glad I do.

 

Ospho is 45% orthophosphoric acid, which will etch into metal. But there is no need for a rust converter or metal etch for vehicles. It has its place but used incorrectly will cause a shit storm.

 

Would appreciate it if you would relate the proper way to use Ospho, Paint Guru, as I'm not able to use epoxy due to over exposure to epoxy years ago that sensitized me to the point I can't even be in the same room with any type of epoxy while it's applied or curing. Once it's cured, I'm OK.
I no longer paint cars at all as I'm 78 and about all I'm up to is occasional painting of parts and pieces used in building something.
I have used Ospho in the past with no problem, but all I did was follow the instructions on the jug. If there's a best way to use it, I'd like to know about it.

 

Guru, again thanks for paint prep school.
As a newbie getting ready to paint, this is all helpful.
I'm following your simple recommendations and having good results.
Epoxy primer over clean metal (ospho previously used, but sanded off). Body filler over epoxy. So far so good.

 

Excellent feedback !! Thanks for sharing the report.

 

Always look forward to Guru's posts. Great info for us 'occassional' painters, as well as the pro's.
One thing a learned back when I was a part time bodyshop grunt, tack the shit out of it, then tack it again.

 

Is Ospho used like a prep-sol?

 

LOL I was just going to write and ask you if you could epoxy bare metal. Now I don't have to.

just a scuff and paint when the metal is bare and you are using epoxy primer correct?

 

Reading the Ospho instructions it looks like it was originally intended to be used with Oil based paint. I'd think the original intended use and still primary use was/is on steel hulled boats and ships where rust is a big problem and where they are quite often brush painted with oil base paint.
From their instructions:

A typical paint application will last much longer after an application of OSPHO because subsequent paint coatings attach themselves so tightly that moisture and oxygen cannot attack the metal. OSPHO is water-thin, and therefore goes on easily and covers a larger area than paint. One gallon covers approx. 600 square feet. Historically, best results have been achieved using an oil-base primer and topcoat. Test a trial sample before using under epoxy or latex-base paint applications. OSPHO is equally effective for exterior and interior work alike and is highly recommended as a pre-treatment coating by leading paint manufacturers

 

No, prep sol is just a degreaser.

 

Yes epoxy primer! Once you have epoxy on, if you prefer urethane, you can always prime over the epoxy with urethane.

 

Do you know if you are sensitive to the a side or the amine in the B side? I have a good dtm urethane primer. Not near as good as a epoxy, but it has some serious bite, and has some corrosion inhibitors built in. Its dtm mix 4:1 as a roll on primer, 4:1:1 as a high build primer, 4:1:2 as a sealer. But need to know exactly what you are sensitive to just in case this product has some of the same ingredients.

If you just want a single component, we are testing a product that has a correct amount of acid and its built into a coating. All someone has to do is reduce to your liking and spray. Its available in any color. Attached are pictures of my 39 olds we did this last year, half the area wire brushed, other half, just degreased. Still has no rust, out in the weather, and was brushed on. Still let me stress its not a epoxy, we built it because we know how much por15 and rust mort is sold. But if you want it pink, purple, black, yellow it doesn't matter, so that's pretty neat. I can get some samples up for you to try on some small pieces and see if its to your liking, and give me some feedback.

 

Here are some more updated pictures, the rest of the body has been stripped now. The shop is using WG55 USC filler (dtm) Today its getting our FORTRESS Semi Gloss Epoxy Primer, will update next time I am there.. Just to give credit where credit is due the car is being done correctly at BACK WOODS Paint, Body and Restoration in Woodland, AL.

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PG, I appreciate all thetrouble you went to with a reply about my epoxy sensitivity, but I don't really do any painting beyond rattle can stuff on brackets, etc. anymore. Body painting I leave to the professionals with spray booths and proper equipment, knowledge and experience.
So again, what I'd like to know is if you have any suggestions on "proper" application and use of Ospho above and beyond what's written on the jug?

 

There was a guy around here in the 70s that would paint a car for $25 plus paint. He didn't even wash them before painting. He did quite a few for used car dealers. One guy had the sheet of paint on the hood peel off and flip up on the windshield.

 

I really don't have recommendations on ospho except dont use it unless its for industrial applications. If you are stripping a car and only want to do rattle can type stuff I would suggest Spraymax aerosol products. I am going to do a start to finish paint job (on a fender) with Spraymax very soon and post on here.
I am sure there are acid etch products that you could use, but I would recommend it be sanded before primer. Some companies cheat and add a oil in the product, and as you know paint doesn't like that.

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Here are some updated pictures, buick was epoxy primed then high build urethane, sprayed topcoat last week with our deep black basecoat. They will assemble this week, and I will get final pics.


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Just noticed that the plastic filler looks like it is directly applied to the metal. I've heard the filler should be applied on top of the epoxy primer. Thoughts/feedback?

 

I have been applying filler to bare metal since the 1960's with no problems ever! That's how all the body shops used to do it. Filler over epoxy is a fairly new deal.

 

I use to paint all emron when I had my shop and it was affordable.I tried to save some $$ and didn't use their prime on a car and then painted it with emron.The car came back within 3 weeks with the paint peeling off. I had to strip the whole car back down to metal and use their primer. Hard lesson learned.DONT TAKE SHORT CUTS!!!!Bruce.

 

On this build, the bodywork was already done, and needed to do as little as possible. The shop does their body work on top of the epoxy, which is what we recommend. There are a good bit of bodyfillers that go directly to metal, and it's OK for it to stick to metal here and there, but definitely needs to go on top of a 2k epoxy.
This is debatable with people, but I will give this scenario and not get into the chemistry side. Let's say you put body filler directly over metal, then did your priming. Most people watersand and bodyfiller is very porous, when you block your primer there will most always be a spot here and there where you cut through the primer to the body filler. That moisture from wetsanding can cause flash rust on the metal below it, eventually causing the bodyfiller to turn loose. At least with a epoxy down first you create a barrier. Now people don't like doing bodywork on top of epoxy because it is hard to feather-edge your bodyfiller. So there is a trade off. But if there were a warranty claim, our epoxy would have to be on the metal. Great question and it's one that make the paint reps and bodyfiller reps want to fist fight!

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Post a video of the fist fight!

 

LOOKIN GOOD. Bruce.

 

Here are some more pictures of finished car.

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