Fiberglass release agent?

Unless you got a lot of curvature, plastic 2" wide packing tape works great.
Or just enclose it in thin sheet plastic so that there are no creases.

wrote in message news:ij2Hc.40976$a24.17578@attbi_s03...
i planning on building a few fiberglass pieces from a mold this weekend
but don't have time to order a release agent.
From looking at the internet, most release agents are wax based products.
Can I just use paste wax for the mold?

Any other suggestions?

Thanks

Dave

On Thu, 08 Jul 2004 03:37:46 GMT, wrote:



Richard Lamb wrote:
wrote:

i planning on building a few fiberglass pieces from a mold this weekend
but don't have time to order a release agent.
From looking at the internet, most release agents are wax based products.
Can I just use paste wax for the mold?
snip
I'm using aluminum as a mold for the part I want to make.
It sounds like the wax may work like you suggest.
There's a couple of seams that I plan to tape off and don't really care
if the tape comes with the fiberglass when finished.

Be careful with tape and resin. Some resins will dissolve the
adhesive which can affect the strength of the part. This is
particularly true of Vinyl Ester resin. (Dow Derakane)

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com


Thanks again for the help

Dave

wrote:


My experience - I built some wingtip plugs using foam board. Covered
them with drywall mud and after final sanding, sealed them with
urethane varnish. The recommendation was to wax them thoroughly with
paste wax and I bought a tup specific for the purpose from Wicks and
proceeded to wax the plug three times, REALLY putting it on carefully
and then buffing it.

I used fiberglass and epoxy resin and wrapped the plug (it was one
half the wingtip, the top part).

The resin bonded quite nicely to the plug and I ripped the plug to
shreds pulling the fiberglass off it. Ruined the fiberglass too.

The missing ingredient? Some kind of release agent on top of the wax.
I bought some PVA from Wicks and the next effort worked fine, after
rebuilding the plug.

Barring a release agent, which you mentioned you do not have, and the
type of plug, if you can wrap the plug with Saran wrap, or something
very similar, it will not adhere to the resin and you can pull it
right off the plug. But if the Saran wrap doesn't fit to the plug
well (perhaps you have trough's to fill that the saran wrap won't lay
into well, then using the urethane tape will work too.

One trick I heard of was to use an air gun to blast between the plug
and the layup to get it to pop off. I tried that and had some success
with the second layup, but ended up using a thin flat stick to wedge
in and push and prod to get things to release.

Corky Scott

I've had problems with saran wrap, Corky.

The kitchen stuff is so thin that the simple mechanical bond will
stick it to the layup tight enough that the saran wrap stretches
and breaks before coming off.

Heavier stuff, something strong enough that it won't tear has worked
well for me. 10 mill or so?

Small pieces of kitchen wrap used to seal off air bubbles, and around
edges that want to stand up, and things like that have worked well.

But for large areas, I'd recommend something stronger.

Richard

Paul Lee wrote:

Unless you got a lot of curvature, plastic 2" wide packing tape works great.
Or just enclose it in thin sheet plastic so that there are no creases.


I've always wondered if small plugs could be covered with heat shrink
plastic like used at Blockbusters on video tapes.

Would sure get the wrinkles out.


Richard

From looking at the internet, most release agents are wax based products.
Can I just use paste wax for the mold?


I would think 3 or 4 heavy coats buffed between each coat to a high gloss
would work OK.... 1 or 2 coats more coats between multiple parts...
Don L. n FTW