Cleaning Fiberglass Mold Release

[kgor]

I've had paint bubbles pop up in the past on a fiberglass fuse even though I pre-cleaned it with soap and water and sanded. Is there a recommended prep technique to totally remove the mold release?

[usmc_VTOL_mech]

Kgor
I have had good luck using steel wool and cleaning with alcohol
Are you sure it was paint bubbles and not orange peel?

[kgor]

Yes. I was mist-spraying, but I still had the problem. The bubbles reocurred in the same spots. I had to re-sand and re-paint a couple of times. Ultimately I won. That's why I'm looking for a cleaning solution. I'm ready to paint a new fuse but not ready to go through that again.

[TomCrump]

To prep my glass parts I wash them with warm, soapy water. After drying them off, I then wash them with denatured alcohol. They are then sanded.

Before I spray primer, the parts are again washed with denatured alcohol, to remove finger oils, etc.

[coosbaylumber]

The mold release agents are designed to resist impregnation via enamels, and such. Thus if you use a contrairy method involving water they are supposed to come right off.

But not always, and not completely.

I have been washing off the parts using disolved TSP, or Tri-sodium Phosphate. This available at a common house paint store in a bag. It sometimes goes by title of wall wash compound. That $2 bag disolves into about 5 gallons, to which you do not need so much. No foaming, and does not make but a few bubbles, but once you stick your hand into it it should feel a bit slick. Watch for what looks to be some color removal and then you know it really is working.

I used to do screen decals and TSP was only reccomended way to remove the film.

Wm.

[Troy]

Are you sure it is a fisheye bubble and not just a fiberglass pore (small open bubble in the glass)??