Is it possible to:
- mask something when spraying the powder coat, and if so, with what?
- powder coat one section of an object (and bake it), then powder coat a different section and re-bake it?
Is it possible to:
Yes, there is a high temp polyester masking tape for Powder Coating.
As for the other question, I’ve never done it and I’m kind of curious myself so let’s see if somebody with a little more powder coating experience chimes in.
Hmmm. I was thinking perhaps it would be possible to mask the areas before spraying and then remove the masking before baking. In this specific case, a little bit of bleed isn’t a problem.
I suspect you won’t get very clean lines doing that. A static electrical charge is the only thing holding the powder in place until it is baked and melted. I suspect pulling off the tape before baking would disrupt the powder along the edge, even if you didn’t rub it off attempting to remove the mask. Peeling off the masking tape might also generate an electrical charge which could disrupt the powder placement.
That being said, the powder’s cheap and scrap steel or aluminum to do a practice run with isn’t hard to come by.
you can do these methods, but as has been stated the powder is barely hanging there; best to leave the masking on until it’s cured in place.
As for masking and then doing a second round of powder over an uncoated section, yes you can. Multiple coats of powder, layering, top coats, etc is typical so it’s not uncommon to re-bake a piece assuming your powder isn’t something special that doesn’t like it.
There are some nice powder coating videos at Eastwood. They show an engine valve cover that is two-toned and how it was masked off with their high temperature tape. They also sell the powders and the tape.
I have masked off logos on cups with a fair amount of success. I make off where I don’t want the powder, spray the cup, and bake it until the powder starts to flow. Once it reaches that point I remove the masking and either finish baking it or bake it for about half the recommended time if I’m adding a second coat. When adding the second coat I have found that hot-flocking gives me the best results. I have also learned not to try to put a lighter color on top of a dark color. I’ve done it but it uses a ridiculous amount of powder to cover the dark color well.
That’s my 2 cents…hope it helps.
Found this to be the case with the eastwood gun and similar guns with relatively low performance; things like the redline gun we have now at DMS would do better without it.
I should clarify. I’m considering two different types of black - and bleed over won’t matter. I want to coat the inside of a small brass piece (about the size of a coffee mug) with “flat” black while it’s reasonably accessible. Then I need to solder a bunch of panels, etc. onto it (making the inside largely inaccessible) and coat the outside using something like satin black, possibly gloss.
They might end up being the same color, but I suspect I have to coat the inside before it is impossible to get the spray into it.
FWIW, I plan to design the parts with a hole or conductive lug to make this easier.
Specific colors not yet selected, but you get the idea. If we have any black available for member purchase that would clearly influence my decision.
In that case I would think masking off the outside of the piece with the high temp tape would work. I would at least give it a shot. I’m not sure how the powder you spray on the inside would tolerate getting baked twice. Seems like it wouldn’t be an issue but I’m sure every powder is a little different when it comes to that sort of thing.
Exactly what I’m using with my home setup…the Eastwood gun. It works great for me…I just had to learn the limitations.
It should be fine, as many powders expect a top coat of clear or multiple layers already. The powder will, however, be able to flow again so it’s susceptible to impression etc just like when first baked.