PDA

View Full Version : PolyTac/Super seam on Powder Coating



coxcub
03-11-2020, 12:01 PM
Folks,

I am well aware of the ongoing arguments with regard to Epoxy v Powder coating on the frame etc.

However I'm interested to hear from those who powder coat whether Poly Tac and Super Seam are OK applied directly or is a further coat of 'Something' else required first?

Perhaps there is a a powder that is resistant to them? - I know not.

All info greatly appreciated

Frank

wireweinie
03-11-2020, 12:05 PM
Powder coating is pretty inert after application. I haven't found anything (chemically) that attacks it. Never had issues with any of the chemicals used in dope/fabric work. Anybody else?

Web

stewartb
03-11-2020, 12:14 PM
Powder coating is pretty inert after application. I haven't found anything (chemically) that attacks it. Never had issues with any of the chemicals used in dope/fabric work. Anybody else?

Web

Not always. The lion's share of my parts including airframe were coated by Advanced Powder Coating and those parts are totally resistant to solvents. A handful of other parts including airbox and baffles were done by Anchorage Custom Powder Coating and when I cleaned my airbox last week with lacquer thinner the rag showed color transfer and the coating became sticky. Not a big problem for this application but a good reminder that not all powder coating is equal.

wireweinie
03-11-2020, 12:28 PM
Wow! That's surprising. I've tried the usual solvents like MEK and have never had so much as color transfer. Maybe yours wasn't heated thoroughly?

Web

mike mcs repair
03-11-2020, 07:59 PM
Wow! That's surprising. I've tried the usual solvents like MEK and have never had so much as color transfer. Maybe yours wasn't heated thoroughly?

Web

I actually seen it on stewarts other pa-12 project when the flap and aileron hangers were powder coated by a guy on the field and acetone would melt it.

Just like using a word like epoxy as a general term. Many different qualities to it.

As to original question those shouldn’t affect it but instead use a contact cement like 3m fastbond 19 to glue fabric to the METAL as it will not dry out and release in a few years as poly tack/super seam will ALWAYS DO
use poly tack for fabric to fabric bonds as instructed, precoat a few coats first though.


Sent from my iPhone using SuperCub.Org mobile app (http://r.tapatalk.com/byo?rid=93960)

phdigger123
03-11-2020, 08:42 PM
All powder coatings are not created equal. There are many types; PVC, Polyester, Urethanes, PVDF, Epoxy, and others. MEK will completely destroy PVC powder.

Steve Pierce
03-12-2020, 06:55 AM
Yep, gotta know what type of powder was used.

coxcub
03-13-2020, 10:26 AM
Many thanks all,

It seems to boil down to using the correct powder format - Epoxy seems to be my best bet.

Frank

phdigger123
03-13-2020, 08:07 PM
PVDF is also fairly resistant to solvent, bit on the pricey side at close to $30 per pound.

astjp2
04-30-2020, 05:18 PM
Good epoxy polymide paint is almost impossible to get anymore too, because of the VOC regulations. I used to use PPG aquapon 35, nothing would attack it, now it is obsolete. Now they have a PPG high gloss epoxy, I may have to try that. My only issue is that I have to drive 200 miles because we have California air regulations and no good quality paint is allowed. Not even oil based varnish....denied!