This is the first year my team is getting our robot professionally powder coated, and we are worried about the coating tolerance for rivets. Our team stock is drilled out to #11 on a 1" hole pattern. The company says their tolerance for the coat is 2-3 thousandths. For other teams who use professional services, do you keep your holes true are do you drill them out to accommodate the powder coat?
We don’t want to be drilling out holes, but we also don’t want them to plug a hundred holes for rivets.
My team has powder coated the past two years, and we’ve just drilled the powder coat off the holes we’ll use for rivets. We don’t change hole size to accommodate.
I like to under-size the holes to “match drill” to the desired diameter during assembly. This makes the powder coat thickness irrelevant. We also use CLR0755 Scotch 4905 VHB tape for extra strength.
If you can I would leave the rivets in the metal in places where possible, this is what we do and the powder coating just give the rivets a bit of extra strength with the coat on top of them
With a number #11 drill, you should be fine. We had #11 holes on our bot this year, got it powdercoated, and 3/16" rivets fit perfectly. The easier solution is just rivet before you powdercoat. I don’t know how your professional service does powdercoats, but ours requires everything be aluminum because of city codes and and the agreement they have with the city.
I would suggest you check with your company if they can powdercoat steel and aluminum or what they can and can’t do.
Also, riveting together before ensures that the piece is all one color and it looks 10000000x nicer.