74-Roadster

Great info and an enjoyable read. I have a question for you guy experienced with DPLF:

1. Is there any issue using DPLF over the bare glass as a starting point to seal everything up.
2. And then apply several coats of high build primer, block, prime, block, prime etc.
3. And then apply another coat of DPLF as a sealer just before applying base?

I've either heard or read that you shouldn't sandwich a polyester primer in-between epoxy.

Thanks, Glenn

Jim Dillon

Glenn, some others may chime in but that is the what I have done on a number of Corvettes and it performed flawlessly. DPLF I believe is a good paint to use on the bare fiberglass. I also put my polyester fillers over the DPLF although there is some debate on that practice. Also you may find that guys at the paint store will tell you that you do not need a sealer prior to the basecoat but I found that I like a sealer and I use DPLF, not too much build just enough to seal it.

As to sandwiching a polyester primer between two epoxy coats there may be some concerns but if you allow drying times in between coats and final seal you will probably be OK. Thes two stage paints today dry by evaporation of the solvents and chemical reaction (hardener). If one paint by chemical reaction dries quicker than the coat underneath it you may trap some of the solvents that should be escaping by evaporation. Check your drying times and allow the paint to dry in between coats. Don't hang a bunch of prime on the panel just before the sealer and you will probably be OK. Body shops are in more of a horse race and many problems rear their ugly head there and then the problem rumors surface. Good luck-Jim

74-Roadster

Thanks for your thoughts Jim.

I'm going to be completing another phase to my C5's rear clip this year and as a part of that, I'll be reworking and repainting my rocker panels and home-made flared quarter panels as well as an aftermarket fiberglass rear fascia. My plan is to seal off the bare glass with PPG's DPLF epoxy primer and use omni's high build primer and then seal everything with House of Kolor's sealer, and paint with house of Kolor's Jet Black and Pro Flo clear.

Eventually, 1/3rd of my C5 will be covered and a dark, Purple Kandy and the rest of the car will be Jet Black.

roger55

Glenn,

You may find this helpful. It's the "Perfect Paintjob" Instructions on the Southernpolyurethanes website.

http://www.southernpolyurethanes.com...ct%20paint.htm

Roger

Scott Marzahl

The thing with the SP instructions is that they do not use any mechanical adhesion with the filler. Do the Polyester fillers really bite that well into an epoxy primer without sanding. Maybe because I've always done it the old way, you know, grind the panel first, lay down some filler or bonding adhesive, block it and then lay down the epoxy or gel coat.

I'd like to learn more about this method and long term success with it.

I'm a fan of Glasurit paint products myself but at the last swap meet I went to SP had a booth there, and my son really liked their bright orange paint, it's way more brighter than hugger orange and it's one of their standard colors. Their prices are a bit more friendly to his wallet too.

The car doesn't need much body work, just a few door dings here and there so I would like to know the best way to fix those with this system. I was going to grind and fill with bonding adhesive first and then shoot the epoxy.

Thanks,
Scott

roger55

Scott,

When you say "door dings", I am not sure what you are talking about. Are you working on a metal car?

I looked at your profile and it looks like the car you are working on is a '67?

If that's true, then I think you should be repairing any '67 fiberglass with matting and resin.

And, yes, SPI is talking about "chemical adhesion" and the success is long term. But, always follow the recommended procedures of the particular product you are using. It is a common practice today to apply filler over epoxy but some still do it the old way and both ways if done properly, are a permanent repair.

And, btw, I have heard Barry Kines, owner of SPI, say he prefers Glasurit to the PPG and Dupont equivalents but all are good.

Roger

Scott Marzahl

Thanks Roger, I'm working on my '67 convertible and my son's '76 Corvette. Instead of door dings in the '76 maybe I should have said chips in the SMC from car doors.

Yes, all my work on the '67 has been with mat and resin and bonding adhesive for filler. I've used Epoxy resin and mat to repair the area where the metal floor panel on the passenger side meets the firewall on the '76. It was cracked and someone had simply stuffed the hole with bondo.

I've used the older Deltron products and Centari but I really find the Glasurit products to go on extremely nice, however they do cost a bit more. I'm looking forward to trying the SP products since I have heard some good things about them.

crazywelder

Hi Scott, I remember chatting with you a long time ago about your projects. I started this epoxy primer method about 7 years ago. I really like this process, especially on steel cars where you don't want to leave the bare body exosed for too long of a time, which is common for weekend warriors. Throught all my years of doing this work, this is what I believe to be the best for steel and fiberglass. Many will disagree, but that's okay. This method (priming first, then filling) gives you the opportunity to clean cover a bare steel body immediately after all the welding and major work is completed to avoid further corrosion. Then apply filler as needed over the epoxy within the recoat window time. As long as you remain within the recoat window time, you can apply compatible fillers onto the epoxy without sanding. If you exceed the window time with DPLF for example, you must sand, clean, and recoat with one coat of DPLF before moving on.

I have not had any failures with this process, and I think problems would have shown up by now, especially in the constantly changing Michigan climate. It is believed that the fillers adhere to the epoxy better than to steel or fiberglass. To me, applying filler over bare steel has the potential of creating corrosion problems because fillers are porous and absorb moisture and that moisture gets through to the steel eventually. With the epoxy primer, you are creating a barrier where moisture can not get to the bare steel. This can be true with fiberglass as well, where a filler or polyester material is used to repair a hole or crack and the filler is exposed on the opposite side of the panel. The exposed filler could absorb moisture and external paint problems could occur. On fiberglass, the epoxy primer will permanently glue down stray fibers and seal the body along with improved filler adhesion properties. There are exceptions on glass bodies in areas where repairs are made directly on the fiberglass, but for minor repairs, filler over epoxy works great. Then you can apply the sanding primers for blocking. And, I use one coat of reduced DPLF as a sealer before the top coats on entire paint jobs, but not on panel spot repairs.

Just to back up what I've described so that people know I'm not making this up as I go, these pics show the final paint steps of a complete rear end sheet metal replacement; the first 2 coats of DPLF, filler applied, sanding primer, and finished product. And the car lives well today with no problems other than some stone chips, but the DPLF did not chip!

Scott Marzahl

Thanks Al!

I totally agree with the moisture under filler or even under primer if the conditions are right. A warm shop 70 degrees or so and warm panel is certainly a must prior to shooting or filling to prevent moisture being trapped.

This site has been kicking around the web for some time and I wondered if it held much substance. I got the impression that you must sand epoxy primer to get good adhesion and if you are sanding/grinding with 36 grit you will be back into bare metal/ SMC or fiberglass in a second.

http://www.roadsters.com/filler/

BondoKing

Seal it with 2 coats of epoxy.. Use whatever brand you so choose.. I use the spi epoxy on everything I spray and like it very much.. Once the car has set overnight, you can either use a polyester primer or a high build 2k ( urethane primer) surfacer to block out the body to perfection.. I also agree with Jim about using epoxy as a sealer.. IMO it is the best sealer you can use

Epoxy is the only oxygen air tight product we use in the automotive refinish industry.. It is the same exact resins as Ecoat that every single new metal vehicle is dipped in from the factory.. The only difference between epoxy and ecoat, is the epoxy is air dry and the ecoat has some solvency differences that require it to be baked on at about 350 degrees..

No matter what project, I think they should all start with epoxy from the bottom up.. you can apply filler or primer right over it

As for the hardner going bad in 14 days.. well I will leave that one for you all to think about.. I have yet to have any issue's using hardner for epoxy that is much older than 14 days, and that includes the solvent wipe test that is spoken of at hotordders, however I dont use ppg epoxy

Georgia1974

For the DPLF users

1. Did you use reducer for the first coat of sealer ?

2. How many quarts did you find you needed for the two sealer coats ?

Jim Dillon

For DPLF as a sealer the ratio is 2 parts paint, 1 part DPLF 401 and 1/2 part DT reducer (I generally use DT870). The way I mix it is to mix the paint and hardener together and allow a 30 minute induction period and then I add the 1/2 DT reducer. Don't know if this is the gospel according to PPG but I have done it successfully this way for awhile.

I generally try to watch my film build so I try to give it a medium coat as a sealer, wet but not as wet as I would if I was trying to lay on a double type coat. I try to get away with this one medium coat and if your gun isn't a complete pig you may be able to get away with a quart to a quart and a half on a smaller car like a Vette. I did it recently a got away with a little over a quart with HVLP gun.-Jim

Georgia1974

Thanks Jim
That is exactly the information I was looking for.