Seal that thing?

Dean Jenkins

Dean Jenkins

Promoted Users
Dang it, I'm close!
Ready to shoot 2K and do final, minor blocking.
I have a combination of black epoxy and grey poly primer.

Everything is scuffed with 180 grit.

Wondering, just get busy with 2K, or a quick epoxy sealer coat, 1:1:1, first, before 2K?

20230125_182904.jpg
 
Two coats of epoxy, unreduced, (1:1) wait the appropriate time, (24 hrs@ 70 degrees minimum) then proceed. You don't want to apply the epoxy reduced at this stage. Full strength only. When you apply the 2K plan on three coats. You may have to shoot three, block and shoot three more. I don't like going more than three coats of urethane primer at one time due to the fact that it can trap solvents and cause the top coat to dieback later. Or use polyester if you want more build. You can only build so much at a time with urethane and not have issues with it trapping solvent.
 
Epoxy at 1:1:1 is intended as an adhesion sealer for base coat, that's its only application in my shop. That said, at this stage, one full coat of unreduced epoxy with a double coat on any bare metal sand-throughs is probably adequate, just in case the epoxy supply is running low.
 
I do exactly what crashtech does. One coat of epoxy over everything prior to 2k, except for filler or sand thru areas, then it's two. When I do my first coat, I just do a shot over the areas with filler or bare metal first. On the second coat I then go over everything.

Exception is if there's filler spots and sand thru's everywhere then I just go with two full coats.
 
Looking good Dean, I'm jealous. If things go to plan, I'll be in final paint by early fall. Just have the passanger quarter panel to strip, epoxy and any body work to do, then epoxy. Once that's done, sand the entire car and spray another coat of epoxy before poly primer.

Keeping my fingers crossed your sanding blocks will be for sale by spring time so I can do the finial sanding with them.
 
'68 Coronet R/T said:
Wow, I told you all I was a garage hack.
That car looks ready for 3 coats of 2k build primer to me. He already has epoxy and 2k on it, so why 2 more coats of epoxy before the 2k?
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For me it's because of the poly primer. You can have a sand-through to the epoxy on final without issue, a sand-through to the poly is more problematic, imo.

But straight to 2K is done at this stage all the time. I think we are just erring on the side of caution because lots of time has been spent on this rig and it's supposed to be top notch. We can't be there to walk around it and evaluate it, nor have we been there during all stages of the prep, so to recommend more epoxy is just prudence from afar, imo.
 
This discussion got me thinking.
If I'm going to put 2 coats of 1:1 Epoxy on, maybe I'll just block that and see how it goes. I think I'm really close and that might be enough.
If more build needed, then I can always do the 2K.
 
Everyone will have their own plan on attack in this situation, but the amount of bodywork there, 2 coats of epoxy will not work as well as you think as far as leaving you with enough to realistically block that car out "straight"

Personally what I would do is one coat of epoxy, then some superbuild and really shape it in. But again, everyone does it differently and its all in the results you are going for. I stopped using 2K primers for anything more than filling scratches once I have all my bodywork be it poly or filler down to 180.
 
Dean Jenkins said:
This discussion got me thinking.
If I'm going to put 2 coats of 1:1 Epoxy on, maybe I'll just block that and see how it goes. I think I'm really close and that might be enough.
If more build needed, then I can always do the 2K.
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If you are going to do that, use 3 coats. Just leave lots of flash time between coats. 2 is likely not enough. Without laying hands on it, we're all shooting in the dark, really.

But I can tell you that when we strip a hood that has dead paint on it, we get away with 3 coats of epoxy then block and paint after a 48 hour dry time. Doing one like that now.
 
Dean Jenkins said:
This discussion got me thinking.
If I'm going to put 2 coats of 1:1 Epoxy on, maybe I'll just block that and see how it goes. I think I'm really close and that might be enough.
If more build needed, then I can always do the 2K.
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I have been thinking the same thing about my GTX. However, I have never used just straight epoxy before and wonder if I should use a larger tip when spraying?
 
Some project I use strictly epoxy on from start to finish and I usually shoot it with a 1.4 or a 1.5 and it lays out nice. Usually shoot 3-4 coats and go from there. For me, anything that is relatively flexible will only get epoxy. I used to always final prime with black epoxy and sometimes I still do, but never tried it for any real type of shaping.
 
Epoxy only is not actually that hard, you just have to get used to the idea that low areas need a little skim of poly putty, or high areas need to be reworked a little, and the thing will have to have more rounds of primer than usual. It's had the effect of making me a little more diligent with straightening.

That's not to say that poly primer doesn't have a place, I do use it on areas that need extra help, but never on a complete vehicle, at least not so far. Maybe if I do something again like an old Impala with lots of long straight lines, I would definitely consider overall poly priming. Or fiberglass parts, those are usually terrible.
 
orangejuiced86 said:
Some project I use strictly epoxy on from start to finish and I usually shoot it with a 1.4 or a 1.5 and it lays out nice. Usually shoot 3-4 coats and go from there. For me, anything that is relatively flexible will only get epoxy. I used to always final prime with black epoxy and sometimes I still do, but never tried it for any real type of shaping.
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Thanks.
I generally use the 1.4 tip for spraying, so I will try just adding a few extra coats and see how things go. When I get that far anyway. Still some metal work to be done in a few areas.
 
I might give Barry a heart attack by saying this, but I have been using an LPH-440 (Iwata's primer gun) with a 1.8 to spray unreduced epoxy, and it works just fine.
That doesn't mean that any other 1.8 gun would be okay, but the 440 seems to do well, and it makes very little overspray.
 
crashtech said:
Epoxy only is not actually that hard, you just have to get used to the idea that low areas need a little skim of poly putty, or high areas need to be reworked a little, and the thing will have to have more rounds of primer than usual. It's had the effect of making me a little more diligent with straightening.

That's not to say that poly primer doesn't have a place, I do use it on areas that need extra help, but never on a complete vehicle, at least not so far. Maybe if I do something again like an old Impala with lots of long straight lines, I would definitely consider overall poly priming. Or fiberglass parts, those are usually terrible.
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I have used poly primer on one overall, a 65 Buick Special Convertible that had a lot of issues.
LH Quarter - Poly Primer.JPG


I used a 1.8 tip which was the minimum size recommended and probably too small.

The '69 Chevy truck, I only need it on the bed sides and used a 2.0 tip.
Poly Primer Front Left Quarter.JPG


I block sanded to get them straight and went right to 2k primer. Now y'all got me thinking I should have sealed the sanded poly with epoxy primer first.
 
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Dean, again there are so many ways to get the same results. If you have the time, go the epoxy route and try it out. I don't think 2 will be enough, but maybe 3-4 will get you really close to what you are wanting as far as results and that could end up being your process from here on out.

Absolutely worst part about this trade is over thinking. Once you have a process that works for you stick with it. There are plenty of good products out there.
 
'68 Coronet R/T said:
I have used poly primer on one overall, a 65 Buick Special Convertible that had a lot of issues.
View attachment 23810

I used a 1.8 tip which was the minimum size recommended and probably too small.

The '69 Chevy truck, I only need it on the bed sides.
View attachment 23811

I block sanded to get them straight and went right to 2k primer. Now y'all got me thinking I should have sealed the sanded poly with epoxy primer first.
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No, you did it just fine. Again, overthinking is the worst! You can do it either way for the final prime IMO.
 
Once its straight, its straight you just need to refine the scratch. I found a particular 2k primer that I really like and it sands really well so I just use that. If I really want to take a good look at the car before final blocking then Ill final prime in black epoxy.
 
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