Epoxy advice
Thread Starter
Melting Slicks
Joined: Oct 2000
Posts: 2,142
Likes: 195
From: Englewood FL
Epoxy advice
I am repainting my 1980 corvette. Used PPG NCP 271 primer wet sanded to 600 paper. Local paint store recommended using PPG white
epoxy over the primer mixed as a sealer as it would make the yellow
color cover easier. Today I sprayed two coats of the epoxy mixed
as a sealer which calls for 1/2 part reducer.
Problem is after the two coats the surface feels a bit rough with some
nibs and some orange peel.
What should I do next? Was thinking of wet sanding with 600 and applying one more coat. Instead should I use a scuff pad (400 to 600
paper equivalent) to remove the nibs and other trash before applying
one more coat. Or something different?
epoxy over the primer mixed as a sealer as it would make the yellow
color cover easier. Today I sprayed two coats of the epoxy mixed
as a sealer which calls for 1/2 part reducer.
Problem is after the two coats the surface feels a bit rough with some
nibs and some orange peel.
What should I do next? Was thinking of wet sanding with 600 and applying one more coat. Instead should I use a scuff pad (400 to 600
paper equivalent) to remove the nibs and other trash before applying
one more coat. Or something different?
Pro
Joined: Apr 2006
Posts: 650
Likes: 14
From: Highland Mi
I would wet sand it with 600 but you may find the paper clogs a bit until it is truly dry. After you sand the outer skin it may sand a bit easier. You really should not have too much texture with a sealer coat. Hopefully you mixed it according to the directions 2 parts of the DPLF and 1 part hardener (I prefer 401) and 1/2 part reducer (I generally use DT870). I do not know what gun you are using or your experience or the speed in which you are laying down the coat of sealer but don't go too slow. Your purpose should not be to lay down a whole bunch of material in a sealer coat but instead to set up a barrier coat. A light and a medium coat is sufficient but no more than two medium coats. Save the heavier coats for the final coats that you will need to color sand. The intermediate coats are more for coverage. Good luck-Jim
Drifting
Joined: Jan 2006
Posts: 1,944
Likes: 22
From: Yooperville MI
A pic would help, otherwise we're working blind here. Jim is right above, you'll need to sand again, but I'm leaning more towards the gun being dirty or not adjusted correctly. Using your description, I vision the "nibs" as small bumps the size of a pinhead which could be dirt or moisture. The "nibs" rough finish could be caused by airborne debris or debris inside the gun. A dirty gun can spew a bunch of debris all at once as it gets loosened up inside.
Excess moisture can cause a finish that looks like dirt also. Do you have a main moisture filter at the compressor and another disposable filter at the gun? If you are using an oil less style compressor, outdoors in the summer, moisture will be your enemy.
The orange peel could be too much air pressure, too wide a fan, or the speed you are going on each pass.
Back to the gun, are the internal passages of the gun clean? You may not be getting smooth air and fluid flow due to debris inside the head or siphon tube. When working with many of the modern paints, especially epoxy, the gun needs to be thoroughly cleaned after use (especially a primer gun) by spraying lots of thinner through it, otherwise it won't spray good.
I know I made several suggestions, so between Jim and mine, you need to figure out what makes sense.
Excess moisture can cause a finish that looks like dirt also. Do you have a main moisture filter at the compressor and another disposable filter at the gun? If you are using an oil less style compressor, outdoors in the summer, moisture will be your enemy.
The orange peel could be too much air pressure, too wide a fan, or the speed you are going on each pass.
Back to the gun, are the internal passages of the gun clean? You may not be getting smooth air and fluid flow due to debris inside the head or siphon tube. When working with many of the modern paints, especially epoxy, the gun needs to be thoroughly cleaned after use (especially a primer gun) by spraying lots of thinner through it, otherwise it won't spray good.
I know I made several suggestions, so between Jim and mine, you need to figure out what makes sense.
Thread Starter
Melting Slicks
Joined: Oct 2000
Posts: 2,142
Likes: 195
From: Englewood FL
Thanks for your reply. Never thought about the gun. I do run thinner
thru it, but have not taken it apart in some time. I use it just for primer
and epoxy so it is overdue for a good cleaning.
I sprayed another coat today after water sanding and did not have
the orange peel problem. I think the problem was caused by the warmer temperature yesturday.
I would like to water sand this last coat with 600 before applying the
color. Any problem with wet sanding the epoxy and applying the color
without applying another coat of epoxy?
thru it, but have not taken it apart in some time. I use it just for primer
and epoxy so it is overdue for a good cleaning.
I sprayed another coat today after water sanding and did not have
the orange peel problem. I think the problem was caused by the warmer temperature yesturday.
I would like to water sand this last coat with 600 before applying the
color. Any problem with wet sanding the epoxy and applying the color
without applying another coat of epoxy?
