Hair spray as mold release

Submitted byJohnAbercrombie onWed, 10/16/2019 - 18:19

On my 'to-Do' list for this week was fabricating a new glass/carbon/epoxy seat for my next kayak project (Bjorn Thomasson Njord).
Just a few days ago, I'd read (online) an article from 'Epoxyworks' - the WEST newsletter - about using hair spray in lieu of PVA mold release. No need to get out my (cheap) spray gun to mist the PVA on to the waxed mold, no gun cleanup, and the hair spray (Pantene Extra Hold !  :)Image removed. ) was on sale at my local drugstore. Aerosol can so it sprayed very nicely.

It didn't work nearly as well as PVA. I got the seat off the mold but it was more of a struggle than usual, and I think it was the wax that was doing the mold release job, not the hair spray. Part of the mold - a small spot of gelcoat - pulled away with the seat, so now that must be repaired.

So, definitely not a technique I'll use again.

My shop does smell nice, though! Image removed.

:)

(Cross posted to WestCoastPaddler forum)

JohnAbercrombie

Wed, 10/16/2019 - 20:17

Perhaps newer hair sprays (the article was from 1999) don't contain PVA?

This was suggested by 'Astoria Dave' on WestCoastPaddler, and it makes sense to me.

mick allen

Wed, 10/16/2019 - 20:36

I've heered of

'beach combing', and

'cockpit coaming' and now these fancy dancy boats are gonna haveta have

'seat combing'?

JayBabina

Thu, 10/17/2019 - 07:50

The article reflects the truth. "Several layers of wax etc". For mold release to work well the mold has to be flawless like a chrome auto bumper. I have done a lot of seats from my mold. I polished and polished and polished some more. ALWAYS had trouble removing the glass. I used mold release which worked the worse. Car wax not polished out, _pretty good. Finally, I resorted to using car wax, quite thick and laying a layer of Seran wrap over it getting it as smooth as possible. Works great. Some sticks to the seat but it comes off easily. To remove any stuck wrap, I just give a quick hit with the propane torch and burn it off.

I have a jug of wax that is made to put on cut tree ends so they do not dry faster than the rest of the wood which splits the wood.  It works pretty good for a mold release.  I have never purchased real mold release so I do not have a comparison of what good looks like.  For smaller items like cockpit rings I just use packaging tape.