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General Composites Discussions Composites Talk
#21

I just waxed a plug with 6 coats of Racedout’s stinky PartAll wax :smiley: I don’t mind the smell, it kinda made me hungry lol j/k.

I buffed between each coat of wax. I’ll probably spray 5-6 light coats of pva on top of the wax. This plug/mold is too expensive and time consuming to have it messed up by not releasing properly. I’ve got about 6 hours into the plug/mold construction and am about 1/3rd to completion. 4 - piece mold for a motorcycle fender. I am now looking for something to stiffen the mold and make it more ridged

I’m thinking of making some gussets out of resin and f/g cloth to go around the entire thing… about 25 gussets total. I can’t have this thing flexing or changing shape on me.

#22

Paper rope is the ideal way to stiffen a mould, its simple, cheap and easy to do, and doesnt add as much weight as other methods.

#23

what is this paper rope you speak of and how do you add it to stiffen?

#24

First off, make some test panels to get the right stiffness you need.

Try, Gel coat 30 mils, surfacing veil, CSM, a layer or 2 of cloth, then some poor mans honey comb “Cardboard” with beveled edges and then glass over that too!

#25

Classic, have you tried chemical releases such as Frekote?

#26

so i put 8 coats of wax, and still… the damn part got stuck! got stuck so good to the edges of the part that it ripped some of the mold off. i gotta REDO the whole thing again. i think im going back to epoxy surface coat instead of gel coat. this is fustrating. also, if i let the epoxy sc tac up, i should be fine adding PER after that correct? they’ll bind i think. no?

#27

Not used anything other than simple wax, as its always worked fine for me, so I dont really feel any need to try anything different.

#28

That’s good advice. I think I might go back to that. It worked twenty years ago when I lived in the UK. I don’t know why I ever changed, probably because it only takes a fraction of the time of wax, but hell I think I’ll throw away all my vacuum equipment as well and just make things with bucket’n brush, then I can critisise people for trying to master other tequniques by saying everythings better with hand layup polyester!

#29

As I give the main moulds I use one coat of wax, every 5 or 6 pulls the time and cost involved is minimal.

There is an old saying about running before you can walk, and perhaps this is something that deserves to be borne in mind, whatever you are trying to come to terms with?

#30

That is exactly why I like semi permanants.

Not to mention you can pull a mould off of a part that has 100 grit sanding marks with it. I know of a boat manufacturer that does just that. Moronic if you ask me, but, I guess it works.

#31

so should i go back to using epoxy surface. wtf is wrong here. or is it the partall wax stupid sh@$@# =(

#32

JRL,
Is there a problem with the poly gel coat fisheye’ing when spraying onto a mold that has been sei-permanent released?

#33

The initial mist coat will fish eye if your using a dump gun. It just cant atomize the gel enough. I have to spray a little heavy for the eyes to go away.

If you use a proper gravity fed spray gun to atomize the gel then you will have no problems. I use a DeVilbiss FLG3 with a 2.2mm tip. Its a $50 tip, but well worth it. Thinning the gel with a table spoon of thinner helps.

As far as brushing gel on. I rarely do it. But have had no problems that way either.

#34

Buy some Mequires #88, wipes on easy, wipes off just as easy. You wont regret it.

Theres also the tried and true TR104.

The problem with Partall is that it dries way to quick. And if you let it sit to long its rediculously hard to buff off. You actually can buff all of it off and end up with a stuck mould.

#35

Luisn, what kind of surface finish does your plug or mold have? It should be shiny like glass with no imperfections. Are you buffing inbetween each application of PartAll wax? It does need to be buffed inbetween each coat. Also if your plug or mold is painted the paint needs to fully cure ( 2-3 weeks ) before you wax it and use it. Paint can be dry to the touch but remains uncured for weeks.

Also if you are trying to make a part that needs a multi piece mold that would cause release problems.

I bought an inexpensive “Preval” sprayer to spray PVA with. I’ll let you know how it works.

I may try that paper rope Classic.

#36

my mold is so shiny you can use it as a mirror. i buff every single coat of wax to a shine. still, part gets stuck. the part that got stuck but came out nice (carbon test) was awesome, i wouldnt even have to clear coat it or anything.

#37

Sounds like there might be negatives in you mould. Or its one of those parts that has to be pulled in one direction. Or otherwise it will never come out.

#38

You do need to be aware of the fact that its not difficult to buff the wax away entirely, and reducing the buffing may well cure your problems.

#39

hmm… well first im going to get the tr104 high temp wax. thats step 1…

step 2. for the re-do of the mold im going to do it in Epoxy surface coat as i always have been and when its tacky ill try and put per and hope for the best they stick together! =|

#40

You may find the higher temp wax is more difficult to work with than the std stuff (it tends to be harder).

Why not have a very careful look at the way you are applying wax, and try making a few parts with a small inexpensive mould, and see if you are still getting the same problems?