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dylan

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Yup you are hearing different thing because there is different systems and methods.

For the home DIY guy using 2k urethane primer, you would have done all your block work and happy with it. Then a thin coat of primer on that and let it dry, wait to dry then sand back wet with say 6/800 clean it all down and you are good to top coat.

Other systems are wet coat, you done the bog and block work and you bang a "sealer" coat of primer on and then once it flashes you paint the top coat. You have to be good enough to lay the primer on nice and flat though for wet coating IMO but its a big time saver in some body shop scenarios.

Then there are others where the primer has a window to coat it without sanding, the primer stays chemically "sticky" for say 24 hours where you have a window to coat it without sanding.

Option 1 for most of us though, sand before top coat we are not in the business of speed and production efficiency. Wet coating works great for engine bays, under the car, interior and all that shit where a bit of peel or dust in the finish doesn't matter.

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37 minutes ago, gibbon said:

Are you supposed to do any further prep between priming and topcoat? I hear it should be wet sanded but I hear it needs to be scuffed but I hear to get a topcoat on before the primer is even dried.... 

If its 2k high build primer then wet sand with about 400g. It'll look rubbish if you just paint right over unfinished 2k primer. Then get your surfacing primer on.. 

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My guess is this has been queried somewhere along the line but searching just brings up engine bays. Looking to paint the magnesium engine case for the kombi. Vht eventually falls off, what would be a better option? Epoxy or is that overkill for a block.. 

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At work For water cooled engines we just paint them with the same paint you do the panels in. Motors don't get that hot in the grand scheme of things. I don't imagine an air cooled engine would get any hotter really?

Epoxy and a quick scuff with some scotch brite and then paint it what ever color you want will be quite sufficient

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Yeah epoxy primer holds out to heat better than anything else, really want a top coat on it though. As above basically modern normal car paint (2 part epoxy and urethane) works better than any of the old school engine enamels etc. I had the fancy KBS engine enamel on a few things and oil leaks eat it and peel it off, it takes the heat fine but not engine bay fluids.

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2 hours ago, nzstato said:

Basic question time:  what causes orange peel? How to I stop doing it? less/more paint? less/more thinners less/more air etc

Orange peel is part of painting. Some 2k color and thick high build clears can be loaded on to be smooth but if takes practice to know how much to not get runs.

In the industry we flat and buff almost everything we do just because it's a quick easy way to remove bits of dust from the paint and get the repaired panel looking the same as the rest of the car 

More often than not the orange peel that most home painters get is from either incorrect air pressure (2.0 bar is a good all round setting)* or not putting a wet enough coat on and there isn't enough paint build up to actually self level and smooth out. A slightly wetter coat will often solve this . 

*not an exact setting for every gun. But just a good starting point for the home jobs with cheaper guns 

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Yup spot on, its so hard to see in the garage how thick/thin your 2K clear is going on so you need some experience to see the subtle differences in how you are applying it. Good thing is you can just cheese it on with a shit gun and still get a nice result by sanding and polish.

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47 minutes ago, JustHarry said:

Orange peel is part of painting. Some 2k color and thick high build clears can be loaded on to be smooth but if takes practice to know how much to not get runs.

In the industry we flat and buff almost everything we do just because it's a quick easy way to remove bits of dust from the paint and get the repaired panel looking the same as the rest of the car 

More often than not the orange peel that most home painters get is from either incorrect air pressure (2.0 bar is a good all round setting)* or not putting a wet enough coat on and there isn't enough paint build up to actually self level and smooth out. A slightly wetter coat will often solve this . 

*not an exact setting for every gun. But just a good starting point for the home jobs with cheaper guns 

Thanks, I try to run 30psi (~2 bar), as you say its likely not enough paint to lay it down, I notice areas where I'm better at this.  Just havent got experience to know 'enough' before risk of getting runs. 

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  • 2 months later...

Anyone know where to get epoxy primer in a spray can in NZ, or is it not a thing? 

Want to use it under filler, instead of just filling on straight bare metal, but cant seem to find cans of it anywhere. I dont have a spray gun, and dont need a lot.

When I asked the bodyshop supply place i got the filler and paint from they recommended just etch priming it first, but the internet says thats not a good idea?

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1 hour ago, kws said:

Anyone know where to get epoxy primer in a spray can in NZ, or is it not a thing? 

Want to use it under filler, instead of just filling on straight bare metal, but cant seem to find cans of it anywhere. I dont have a spray gun, and dont need a lot.

When I asked the bodyshop supply place i got the filler and paint from they recommended just etch priming it first, but the internet says thats not a good idea?

I buy Durepox as a 2-part from Resene Automotive (RALI) in Naenae.

Have sprayed it, but mostly mix and brush for small areas as Spenno says.

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1 hour ago, tortron said:

 

 

ive got an old tin of durepox with some dregs in it. How big of an area do you want to paint? if you have 2k hardener already i can decant it into a bottle and post it - then you can just brush it on

Thanks, but having never done bodywork before I have nothing, so will do as below

27 minutes ago, Nominal said:

I buy Durepox as a 2-part from Resene Automotive (RALI) in Naenae.

Have sprayed it, but mostly mix and brush for small areas as Spenno says.

And go here and buy some. Its only a small area, so bushing sounds like a good plan.

Thanks lads.

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Where is the area? Is it going to get wet all the time or is it in a dry area? I brush on epoxy all the time (with PPE). But if I was literally never going to need it again, and the area wasn't going to be a wet area i'd probably zinc-it, then primer over that, then bog then primer then paint.

Yeah I know it's not a legit as epoxy then bog then epoxy, but i've zinc-it'd shitloads of stuff I have outside and with a decent top coat i've had zero issues. Just offering up a cheaper, easier solution IMO. I see zinc-it not even top coated on galv gate frames all the time, looks fine. Is actually what I did for my gate frames, weld, zinc-it, then top coat. Haven't seen any issues with it so far.

Totally depends where the repair is, haven't seen it mentioned.

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On the rail, above the front door, between top of door and roof, before the B pillar. It'll get wet with rain, but no road grime. Had been repaired before, but rusted from inside out and I popped the bog pimple and stuck the screwdriver right through. Its since been cut out and new patch welded in, but the previous repair used a couple mm bog to shape the rail properly, so ill need to bog it again since I ripped all the old bog out (and im not so flash on shaping patches). I suspect the old bog was straight onto metal as around where the rust popped out the metal on the outside was all really badly pitted too.

I have zinc-it here, as well as etch and high build primers.

I dont have a habit of doing body work, so chances are anything I buy will sit on the shelf until it goes off and gets thrown out, after being used once.

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