Epoxy/filler/featherfill poly primer

RosharonRooster

RosharonRooster

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On my jalopy I'm currently in the filler/epoxy stage of the shell. I plan to continue this stage using 80 grit and assortment of blocks until I think I'm done with filler. ..I've been hitting bare metal in areas, and spotting in epoxy and continue the process. I want to continue this process using 80grit, then lock down the entire thing in epoxy. Would it be best to put the poly primer directly over the epoxy the following day without doing anything,....or.blocking the epoxy with 180 then poly....am I over thinking this??
 
I think for poly you want to allow the epoxy 48 hours before spraying rather than the 24 for filler over epoxy. Following this as I am at the same stage. Ill ask a few other question for next steps past this as well:

what grit do you block poly to? 180 or refine further to just cover in epoxy sealer and go to base. Or is it better to do 1-2 coats of unreduced epoxy over final poly blocking then sealer? if so should the unreduced be refined and to what grit before reduced epoxy sealer?
 
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aviator8 said:
I think for poly you want to allow the epoxy 48 hours before spraying rather than the 24 for filler over epoxy. Following this as I am at the same stage. Ill ask a few other question for next steps past this as well:

what grit do you block poly to? 180 or refine further to just cover in epoxy sealer and go to base. Or is it better to do 1-2 coats of unreduced epoxy over final poly blocking then sealer? if so should the unreduced be refined and to what grit before reduced epoxy sealer?
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Me personally, as an amateur, I block poly with 80 grit only, but I might change my practice on this project and start with 180 instead of 80
 
I view Polyester Primer as spray on body filler. Hence block sanding with 80 grit to get the panel flat and straight.
If needed, and it usually is, I will shoot 2k build primer after that, guide coat and block sand with 320 grit.
 
'68 Coronet R/T said:
I view Polyester Primer as spray on body filler. Hence block sanding with 80 grit to get the panel flat and straight.
If needed, and it usually is, I will shoot 2k build primer after that, guide coat and block sand with 320 grit.
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Any shrink back with the 2K over the 80 grit?
Decades ago, before urethane and epoxy, I used to shoot lacquer primer over 80 grit filler. Then block that and more primer, etc.
I always gave it plenty of time to dry. I got away from that with urethane primer because of shrinking, using 180 prior to primer and still noticed some shrinking. But that wasn't SPI 2K primer. I have used epoxy primer for everything, not very much 2K so the reason I ask.
 
I
metalman said:
Any shrink back with the 2K over the 80 grit?
Decades ago, before urethane and epoxy, I used to shoot lacquer primer over 80 grit filler. Then block that and more primer, etc.
I always gave it plenty of time to dry. I got away from that with urethane primer because of shrinking, using 180 prior to primer and still noticed some shrinking. But that wasn't SPI 2K primer. I have used epoxy primer for everything, not very much 2K so the reason I ask.
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I have noticed shrinkage with 2k over 80.
 
Me personally I start with 150 on poly. I used to start with 80 but I hate refining scratches after 80. If I block poly with 80 I will always reprime with poly again. At least starting with 150 if the panel comes out straight after one blocking with 150 I can go straight to 2k or epoxy if I go that route.

Plus I feel like poly sand so muck nicer with 150 than 80. Just an opinion.
 
Ok guys, please listen to the pros. Do not use my method. It’s pure backyard hackery and you will not get good results.

Don
 
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aviator8 said:
any is


Any issue with this
epoxy, filler, epoxy, poly (rust defender), epoxy, epoxy sealer, base, CC?
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If it were me I’d just be stopping at your last epoxy step and not do the sealer. But I also wet sand the last epoxy coat before base.
 
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