Primer guestions

[mallard]

From the forum I see that many people spray there own cars, and some people are professional body people. My concern is about the primer that was put on my car about 18 months ago. Do to some missunderstanding the shell was not sprayed with the primer of my choice. I wanted a 2 part epoxy, and got Limco 834 Zinc Phosphate Primer. The person who did the work is no longer around, and everybody else does not want to spray over the primer on the car.. From the DATA Sheet many types of top coat can be used, all Limco products though, ranging from Synthetic enamel, Acrylic enamel, urethane, single stage, and base coats. After speaking with reps from Dupont, and PPG they will not recommend their products be put over the Limco primer. Is my only route to restrip the shell and start over? Or can some type of sealing primer be put over the Limco? I feel I should restrip the car and start over.

 

[DrEntropy]

Ooof.

This is just a WAG from me but I suspect a block sand with #600 then a coat of epoxy primer should get you where you need to be. Others may have better than a guess, tho.

 

[TR6oldtimer]

If all you have on the car is Limco 834 Zinc Phosphate Primer primer, it is just a pre-coat, acid-etch primer, not a primer sealer as the two part epoxies are. This particular product was designed to be laid down first to form an adhesion layer between the metal and the surfacer (sand-able) primer, which should have been applied within a relatively short period over the pre-coat. The surfacer primer is the coat that gets sanded before sealing or top coating.

The problem with pre-coat primers is they tend to be porous and can allow moisture to penetrate to the metal and start the rusting cycle. If this has occurred, some time down the road the paint will lift. I think the length of time since the primer was applied is the reason for the apprehension of the paint suppliers.

The good thing is I see you live in Arizona, an arid region. So if the car was kept in a garage, the paint would not have been exposed to a lot of moisture, but it will have oxidized.

So, minimally, I would sand the flat surfaces as Entro has suggested, and using a course scuff pad, go over the other areas, clean well, then spray with an epoxy primer compatible with the surface primers and top coat system of your choice. You may also want to sand down to metal a flat area like the trunk lid or rear deck to see if rust has started. Obviously, if rust, or a hint of rust is present, then the pre-coat has to come off.



Your primer...
https://partsplustools.com/pdfs/limco_single_stage.pdf

 

[mallard]

Thanks Ray and the good Dr. for the information. The car has been in a dry garage the entire time , and I see no signs of rust. A very lite coat of primer was put down. So lite that you can see color variations in the primer. Some ares you can see clean metal thru the primer.

The shell was professionally blasted before the primer was put on, which seems to protect the metal itself from rusting. Soom areas of the shell that did not get hit with any primer still show no signs of rusting.

I hope the car will be ready for paint by the end of summer or fall. Then the temps will have come down, and the humidity very low.

And thanks for the link Ray.

 

[TR6oldtimer]

Keith, you are quite welcome. The good news is it looks like you are a go. Instead of sanding, use a fine or medium scuff pad to roughen the surface or leave it to the painters to do.

 

[hondo402000]

speaking from experience, save yourself a lot of grief. at this point forward pick a manufacturer for your paint and stick with their paint system. 2k primer, sealer, base and clear, I would also do a test, get some primer thats currently on your car, then your 2k primer, BC CC, the smallest quanties you can get then get a piece of sheet metal and spray it like you are painting your car and make sure its all compatable, might cost you 150 up front but knowing it will work will save you a lot of trouble.

all 2 part fillers and 2 part glazes are compatable with most paints but ask

Hondo

 

[MDCanaday]

BTDT ,if it were me, in my shop,I would test a panel with a similar etching primer.These are very often the same thing chemically, but also will etch into each other without sanding/scuffing.At that point you can just apply the primer of your choice,and then go, wet on wet with color on the interior bits of the tub.
Your now done in a day vs several days.Dont forget the all important step of seam sealing as soon as the primer has flashed off.We use Kent 6000 epoxy,but there are lots of others.
MD(mad dog)

 

[mallard]

Thanks Hondo for the ideas I was kind of thinking on the same lines. Some test areas would be cheap insurance. I followed your painting post and the problems that you had with materials no working together. Lesson learned on my part without the bad experience.

MD thanks for your ideas as well. The idea of a primer that will etch into the primer that is on the car would save alot of work. It looks like test areas are the best way to go with this, without restriping the shell. I've never used Kent sealers before but will look into them. Had good luck with 3M products in the past.

 

[alfa33047]

Mad Dog, why don't you just move to Arizona during the winter and paint cars for us? We don't have snow in Phoenix and nice winter weather. Think about it. Bill C. Mesa, Az.

 

[Got_All_4]

I hear the old pay me now or pay me latter commercial echoing in the back ground. A little prevention now is worth many hours and dollars latter on when the car is finish and you want to be driving it.

If there is that little primer it, it couldn't be that big of a job to strip it off. Just get a DA sander pneumatic or electric with some 320 sandpaper and DA the entire car. That would ensure that you get the primer off and no incompatibilities down the road. Also it could take care of any minute rust issues you can't see. Then do what HONDO suggested and pick a paint manufacture and use the products start to finish.