Sandwiches ie epoxy sandwiches that is…..

[Moparfiend]

So I have the car in epoxy primer now and it looks good and ready for final blocking. I am planning to shoot it with a high build primer over the epoxy primer.
I am concerned about what to lay over the high build polyester primer when I am done. I know the polyester primer is porous and I would like to seal it as a sandwich but I don’t know what to use compatibility wise.

Any advise from you guys who do this semi-regularly?

 

[69L48Z27]

What products are you using? Some are thinned epoxy as sealer and other lines have sealer.

 

[Moparfiend]

What products are you using? Some are thinned epoxy as sealer and other lines have sealer.

I used a two stage 1:1 DTM epoxy primer and next would be Eastwood’s Contour Polyester High build primer. Its out of date so it’s possible I could use a different one if it doesn’t lay down. TBD.

 

[Llamaback]

If you plan to block sand right away do not topcoat the high build polyester. If you want to wait to block it out I would use a 2k urethane primer surfacer. The epoxy on top would be hard to sand and gum up your paper.. you want good fresh sandpaper for your polyester so you can see where your low spots are at and get them filled quickly in the process.

 

[1967coronet]

Seal it before paint with deltron ppg DP50 if you need a grey sealer, use DP90 if you need a black sealer.
You will use deltron Ppg 402 activator and a 860/870 reducer.
Mix 2-1-1.
Another good sealer is deltron ppg 3055
With 3030 activator. Same reducers ,mix
4-1-1
A 400 grit surface,plain water wash and dry twice , next day blow gun every crack and crevice then grease and wax remover .
After the flash off tac it twice.

 

[Moparfiend]

Eastwoods Contour Polyester data sheet does not indicate compatibility of any top coating sealers. I trust both above recommendations but I have no way to verify compatibility. So I want to feel secure that I won’t have a delam issue later.

Am I making a mountain out of a mole hill here?

I do have a gallon of Upol UP2253 Urethane 4:1:1 primer on my shelf but not sure that this is considered a sealer.

#Stillunsure

 

[eldubb440]

I stay away from "filler primers" all together. The key is to use an epoxy that fills adequately, and sands easily. SPI epoxy is the only primer on my bench, but there are others (An aerosol can of etch comes in handy for bare edges and such). Couple coats of epoxy over my bodywork, dry sand with 120/180, touch up any body work and recoat; sand again with 320/400/600 when ready to paint

 

[Bighouse]

I stay away from "filler primers" all together. The key is to use an epoxy that fills adequately, and sands easily. SPI epoxy is the only primer on my bench, but there are others (An aerosol can of etch comes in handy for bare edges and such). Couple coats of epoxy over my bodywork, dry sand with 120/180, touch up any body work and recoat; sand again with 320/400/600 when ready to paint

Solid advice right here. I’ve been let down by urethanes of varying brands, I’ve tried them all, and switched to SPI epoxy. I’m more than happy.

 

[Moparfiend]

So let me get this straight. Your saying that your blocking SPI epoxy primer. I have not seen this recommended before. I am not doubting I am just surprised as I know that epoxy primer in general is not all that great to sand ie clogging paper and its rather hard when fully cured.
SPI primer sounds a bit different. I will call them and order their epoxy primer. Was planning on using their Clear actually as JK recommend that and their Base color. I just am planing on using a color that I don’t think they have (Vitamin C or lighter).

Oh and after looking carefully into their website they actually have a high build version of their epoxy primer which might be advantageous for me.

 

[eldubb440]

So let me get this straight. Your saying that your blocking SPI epoxy primer. I have not seen this recommended before. I am not doubting I am just surprised as I know that epoxy primer in general is not all that great to sand ie clogging paper and its rather hard when fully cured.

I learned using epoxy primer in the 80s and have evolved the process for ever, back then it was Glasurit, but that stuff was/is super pricey. SPI is awesome bang for the buck, so it is all that I use.....

I find that multiple, lighter applications (as opposed to one big fat layer) pretty much eliminate any future shrinking and sinking into the body work. I paint the job, buff it, and it stays that way.

Another advantage is you can open up an area of epoxy, do what ever work you need to do, and seal it back up.

last job I did, the fenders and hood were really rough, bordering on junk but not rusty....... someone had sandblasted them into oblivion. Lots of work, but came out great
after sealing bare metal I rough in and glaze my filler work, I do not care about breaking through the initial epoxy coat because it gets recoated with epoxy anyway. Then I block it, glazing putty where needed, and reseal it......as many times as it takes, finer sanding each time....... these fenders and hood probably went 3, maybe 4 rounds in some places

 

[Moparfiend]

I learned using epoxy primer in the 80s and have evolved the process for ever, back then it was Glasurit, but that stuff was/is super pricey. SPI is awesome bang for the buck, so it is all that I use.....

I find that multiple, lighter applications (as opposed to one big fat layer) pretty much eliminate any future shrinking and sinking into the body work. I paint the job, buff it, and it stays that way.

Another advantage is you can open up an area of epoxy, do what ever work you need to do, and seal it back up.

last job I did, the fenders and hood were really rough, bordering on junk but not rusty....... someone had sandblasted them into oblivion. Lots of work, but came out great
after sealing bare metal I rough in and glaze my filler work, I do not care about breaking through the initial epoxy coat because it gets recoated with epoxy anyway. Then I block it, glazing putty where needed, and reseal it......as many times as it takes, finer sanding each time....... these fenders and hood probably went 3, maybe 4 rounds in some places

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View attachment 1395675View attachment 1395676

Thanks. So SPI’s epoxy is different in that its highly sandable right?
I gotta ask. What paint color and mfg is that? Also what clear is that? It looks great! Is that fj5 or fj6?

 

[eldubb440]

Thanks. So SPI’s epoxy is different in that its highly sandable right?
I gotta ask. What paint color and mfg is that? Also what clear is that? It looks great! Is that fj5 or fj6?

yes, sands easy without clogging paper. I hate dust, but I sand it dry; it's fast, and I can see as I go. It also keeps water off any bare metal and filler. the above panels were sealed over metal, bodyworked, primed, sanded with 120/180 on durablock touched up with glaze and reprimed. Then sanded with 220 on durablock and reprimed.... at this point they are pretty much laser straight and I do the next sanding with 400 on a DA with an interface pad; maybe followed with 600 wet if metallic color.

the above is SPI high siolids clear over Wanda (akzo nobel) basecoat. SPI clear works with any quality base...... and yes, whatever the code is for 70 limelight

the top banana and plum crazy below are matrix basecoat. I slide a little 800 wet over base to de-nib between coats when needed. Base can be a pain in the *** clogging paper, I try to keep sanding it to a minimum

 

[eldubb440]

I also recognize other people achieve nice results with other products and other techniques.......... I'm just sharing what has worked well for me over the years

 

[Bighouse]

I also recognize other people achieve nice results with other products and other techniques.......... I'm just sharing what has worked well for me over the years

Yes, just ask any body guy- their way is the best way…..

 

[Moparfiend]

Yes, just ask any body guy- their way is the best way…..

Just about true for anything. Look for jobs like this for the average guy that doesn’t twice in his lifetime. Maybe it’s nice to get input from people who do this on a more regular basis. That experiences worth a lot.

 

[Llamaback]

I really like eldubb440s methods with the SPI epoxy, I will have to try that out sounds like its a great product and would simplify things for me. If it really sands that well I would absolutely do things eldubb440s way. I have used lots of the eastwood epoxy and really like it, but it gums up sandpaper no matter how well cured it is. In my opinion you are fine to use the polyester primer, just don't abuse it and allow proper flash off times between coats. Once your polyester is down and you have sanded it you are good to topcoat it with a 2k urethane primer surfacer or more epoxy primer. The epoxy sprayed as a sealer would probably seal your polyester the best. I have done my paintwork on top of 2k urethane primer surfacer that has been block sanded to 600 grit and have had really good results. I have also used polyester primer under my 2k urethane surfacer and had good results with that too. If you sand your polyester primer anything will stick to it.

 

[Bighouse]

Just about true for anything. Look for jobs like this for the average guy that doesn’t twice in his lifetime. Maybe it’s nice to get input from people who do this on a more regular basis. That experiences worth a lot.

My comment was sarcasm targeted at the Dubb.

I went back and forth with eldubb440 a while back about epoxies when I made the switch. I’ve been in Autobody world my entire working life so far. Almost 25 years. I’m 40.
The switch to epoxy was big for me being set in my ways of 2k urethanes and such.
The urethane surfacers and sealers still have their place for me (not much anymore) but I find myself epoxying almost everything.
The SPI film build appears close to what I’m used to with urethanes and SPI will not clog you paper or gum up. These were all things I worried about. My old cars will not see any urethane.

 

[eldubb440]

the only downside is keeping it warm, but I manage

 

[Moparfiend]

Hey @eldubb440 are you using a sealer between the primer and base coat? Are you using a chemical bond in the window of the primer or mechanical bond? If mechanical bond what final grit before paint do you use?

 

[eldubb440]

Hey @eldubb440 are you using a sealer between the primer and base coat? Are you using a chemical bond in the window of the primer or mechanical bond? If mechanical bond what final grit before paint do you use?

I finish sand with 400; 600 for the lighter metallics.......followed with a sealer coat just prior to paint

SPI epoxy with a little reducer as a sealer (it's all on the data sheet)....... other than a can of aerosol etch for little things , SPI epoxy is the ONLY primer I use

when I de-nib the base after a few passes, it also de-nibs the sealer coat

To use as a Paint Sealer: To use this epoxy as a paint sealer, mix it 1:1 with activator and reduce 10-50% with the proper temperature range urethane reducer (this is very important), induce for 30 minutes and spray with your base/clear gun. Spray one wet coat ONLY, let it sit 2 hours then apply paint. For sealing of a potential problem paint job, apply two coats of epoxy with proper flash times between coats and let it sit overnight before painting. You may basecoat over Epoxy Primer reduced as a sealer from 2-48 hours without sanding. After 48 hours scuff with a gray scuff pad or equivalent first.

https://www.southernpolyurethanes.com/_files/ugd/8ced3e_2e1da7dc5da34c94bb9c9704d8464b44.pdf