Chris_Hamilton
Trying to be the best me, I can be
IMO Evercoat's 4:1 poly primers are far superior to G2 or Slick Sand. I'll only use the 4:1's in the future.
N
northerndave
So you'll go back to epoxy after poly? rather than 2K?
Interesting, I like that.
Well, I have christine ready for spi epoxy. It's all torn apart, its on the frame but I have the frame and empty body up on a body cart. The fenders, doors, hood, deck lid are all into their 2'nd session of spi epoxy, ready for a third with increasingly finer grit blocking each time.
The body though, It's ready for it's first round of spi epoxy. I don't think I'm going to get away from using some poly over the epoxy on the body. What't the process for poly over spi epoxy? Do I have to give it like 48 hrs or better before I put the poly over the epoxy? I'll use evercoat 4:1 finish sand.
jlcustomz
evil painter
A good 2 days plus dry time is best, especially if colder air temps are slowing dry time.
Some people only use epoxy as a base & final primer on good areas & poly primer in between where you need the extra fill qualities. Epoxy is a higher quality final primer than 2k & if you get all the filling & sanding done with poly, then you don't have to use a 2k over it. 2k's biggest advantage is quicker drying times over epoxy.
Some people only use epoxy as a base & final primer on good areas & poly primer in between where you need the extra fill qualities. Epoxy is a higher quality final primer than 2k & if you get all the filling & sanding done with poly, then you don't have to use a 2k over it. 2k's biggest advantage is quicker drying times over epoxy.
crashtech
Combo Man & Mod
In cool temps it's really a good idea to wait quite a while between epoxy and poly because poly is WAY faster than epoxy, generally fast products over slow is a no-no unless the slow product is cured out. I would say wait until the epoxy sands without clogging the paper, that is a better way to tell, since time is too related to temps to say for sure. In the winter that might be up to 72 hours with 65° panel temps.
N
northerndave
Yeah I'm going to give it plenty of time. I don't have a bake booth and my outside temps have been very cold (-30 this morning)
I don't usually do any spraying unless we have outside temp close to 20 above zero, otherwise it's too hard to keep the air temp up in the shop with the booth drawing that cold air into the building.
Next week we are supposed to see 20's above zero. I'll wait till next week, plenty of other things to do. I have a 69 ranchero that needs extensive structural work up front, both front torque boxes, forward frame repairs, rockers etc. (hateful)
I'll work on that stuff then jump back to christine when it warms up next week.
I don't usually do any spraying unless we have outside temp close to 20 above zero, otherwise it's too hard to keep the air temp up in the shop with the booth drawing that cold air into the building.
Next week we are supposed to see 20's above zero. I'll wait till next week, plenty of other things to do. I have a 69 ranchero that needs extensive structural work up front, both front torque boxes, forward frame repairs, rockers etc. (hateful)
I'll work on that stuff then jump back to christine when it warms up next week.
S
Superchief
If you had properly prepped and epoxy primed the panel and were looking to get your body panels laser straight with no "large" dents/dings visible in the panel, would you "skip" skim coating a entire panel with spreadable body filler and use sprayable polyester instead? Or would you sand panel with 180 grit, spray another round of epoxy, and repeat the process working your way up to say 320 grit sandpaper and just use high build primer and continue from from there?
I think what you're asking is if the panel has damage, should you skim coat with filler or use poly.
If at all possible, you would want to get your metal work good enough so you don't have to skim coat an entire panel, but we all know that it happens. With that said, I usually spray poly right over my epoxy (48 hours later). Then I scuff the poly a little and put the filler over the poly. I may get a slap for saying this, but I don't even scuff the poly if it is pretty fresh. It always feathers fine and I've never had a problem. This method seems to work a lot better for me, as opposed to putting filler over the epoxy because I have way less rub throughs and I get much more done in one step.
As crash mentioned, you don't want to use poly where it is not needed. If I have areas on a panel that need it which are adjacent to areas on the same panel that do not need it, I either don't spray those areas or I mask them, depending on the situation. Keep it out of hard to sand areas.
S
Superchief
Thanks for the replies. Considering giving painting/bodywork a try myself on my personal project a 1978 Pontiac Bonneville. Amazingly the body is fairly decent with just a few "dings" here and there and no real "body damage" or rust repair to speak of. Yes strum456... basic idea was to get metal "as straight as possible" before considering anything and moving on from there. I had a misunderstanding behind the idea on the purpose of using polyester primers, and think i might be skipping it since i feel the body "is not that bad". Plans are for a black bc/cc paint job and looking to get things as straight as possible.... we all know (even with my inexperience) they show everything and are a pain in the ass in may respects.
As you are describing yourself as "inexperienced", there is usually a lot more work to do than one would think. A good place to start would be with 2 different colors of primer. A best case would be to get a gallon of white epoxy and a gallon of black epoxy. Spray one or two coats of black on the bare metal, followed by a coat of white, or gray. Then give it a "light" blocking with 180, making sure to stop any time you start to see even a hint of black starting to show though. At that point, you will know exactly how much work needs to be done.
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northerndave
Doors, deck lid, hood and fenders are off the car and these parts will be very good after the 3rd session of epoxy. Some are actually done, none of those panels needed spray poly. But I think I may lean on that old crutch for the body itself. This is a big car, 1958 plymouth (think christine movie car)
S
Superchief
Thanks again for the advice as that's just about the direction i was considering starting with. Figure i will start with having the car dustless blasted to see exactly what i'm starting with, get things prepped properly,and put it in epoxy primer first. I'm not looking to rush things so i figured i'd give it a blocking session (or two depending) and from there if i feel it's going to "require more work than one would think" and i feel it's way beyond my capabilities to get things the way i expect them to be (which knowing my meticulous and anal standards is damn near perfect) then i"ll re-epoxy prime everything and off to the resto-shop it will go.
C
chevy_power427
Just tried Evercoat's super build polyester primer. It's a 4-1 just like finish sand, sprays so easily out of a 2.1 gun, just slighly thicker than finish sand. It seems to build good and lay smooth. It's a little bit harder to sand than the finish sand, and tends to have a very slight gummy feel on the surface. It needs to be started with a 100-120 grit, but afterwards, 180 to 320, no problem. I will be using this in the future rather than finish sand.
I have used the Evercoat High Build recently. It says 1.6-2.2 needle, but my air valve was messed up on my primer gun so I reduced it 10% with acetone (per the instructions on the can) and tried it out of my LPH400 with a 1.4 needle. It laid down super smooth, although I'm sure I didn't get as much build as my primer gun would have had. I can't comment on sanding since I just don't have the experience to know any better. I know the epoxy sands easier once it's cured, but that's about it. I might try a can of the Evercoat Finish Sand next... not sure.