Following the Polyfiber manual to the ‘T’.

When the tapes are first sprayed with reduced Polybrush tiny bubbles form and harden on the surface of the tapes. Even if I brush on the product (instead of spraying) the bubbles appear randomly on the tapes but not on the adjacent fabric.

It is strange that some pieces will have no marks on the tapes at all while others have numerous ‘bubbles’ that have to be dealt with. In the end they clean up OK, but it is a lot of extra work that I would like to avoid.

Tried reducing the Polybrush to 4:1, adding Blush Retardant, changed the heat in the shop, changed the humidity in the shop.

Nothing has worked so far, any ideas? Has anybody else experienced this?

Thanks to everyone who helps.

You didn't brush on enough polybrush onto the fabric before you put the tape on, so air is coming up through thhe fabric and forming bubbles.

Or, you had some contaminants on the surface of the fabric which is screwingup your tapes. Sweat, dirt, spilled soft drink, whatever.

There is a lubricant that they use in the manufacturer's weaving loom so that the loom can run faster without problems. You have to scrub this lubricant off the surface with acetone or MEK or reducer before you start the coating buildup. That trick was taught to me by an old hat who specialized in the Stits (polyfiber) process.

I'm starting on my tape tonight, so I'll let you know if I have any brainwaves.

Ps. I think you missed a couple of forums

EZFlap is exactly right. Not enough precoat and maybe some "sizing" contamination. It's actually covered in the Polyfiber manual if I remember......

Yep, you probably didn't spray on enough base coat.... but thats water under the bridge. You can fix that, use the small iron on a lower heat setting and iron the bubbles out.... you'll be amazed at how many errors and problems you can fix using heat... don't despair.... just drag out the iron and have lots of patience.

gunny