Lets reverse the question.
Why should you not go into the business of powder coating?
Don’t do it if you have no customers wanting your services.
Don’t do it if there are too many powder coaters located in your market area.
Finally, don’t do it if you have little interest in the art of powder coating.
I know this inquiry is not current but it is something which needs addressed again.
Of course IF the powder coating is CURED on the oven wall it will take more than a vacuum cleaner to remove it.
Some oven walls are stainless steel and if clean will reflect IFRA RED HEAT in the case of this type of oven. If so, keeping the powder coating off of the walls are very important.
So,be sure powder fines will not be flowing into the oven in the first place.
Can’t be much help here.
Nor experience with m seal, etc.
Your 180 figure is most likely C. not F.
But either way the expansion/contraction of
the sealer will come into play.
Trial & error should be your approach.
Most Coating Powder Manufacturers can provide you with this kind of information.
Carbon based products of any sort will burn at some temperature.
I used to suggest that wood products give off gases when burned and so will powder coatings.
None of the gases are intended to be inhaled by humans or animals.
Congratulations for wisely choosing to add
powder coating to your services.
It should be a good put-to-gether for you.
Remember that preparing (cleaning/grit blasting)
the part for powder coating is most important.
Your customers will expect you to produce a silk purse from the sows ear. Good luck.
Most powder coatings can be recoated.
If you have already cured those products you
should sand the finish before putting on the second coat in order to improve the interface adhesion of the two coats.
Another fix would be to preheat the coated parts and recoat.
In each case you would end up with a thicker coating
which hopefully will not be a problem.
Your oven bottom will act as heat sink,
that is, obsorbing the heat produced.
But if will also help contain the convection
heat by deflecting it back to parts to be coated.
Of course not as a well as an insulated metal floor.
So, it can be done but not without an extra cost with each production run.
Why not mechanically clean the part yourself.
Of course you can adjust your price accordingly.
The customer has taken a leap forward via laser technology and should not mine a small increase coming from you.