stuck plug

General Composites Discussions Composites Talk
#1

I built/made a new plug and mold this past few days. Here are some photos. The scum inside the mold cavities is PVA, clay, and wax.

http://s210.photobucket.com/albums/bb186/Fastrr_photos/?action=view&current=heelguardplug2.jpg
http://s210.photobucket.com/albums/bb186/Fastrr_photos/?action=view&current=heelguardmold1.jpg
http://s210.photobucket.com/albums/bb186/Fastrr_photos/?action=view&current=heelguardmold1.jpg

What is the best way to clean the mold, free of clay, PVA and wax?

How should I repair the tooling gel coat; it has chipped out in one spot ( 1/2" x 3/4" chip x1/8" deep).

After the cleaning and gel coat repair, what are the next steps i should take to complete this mold? Should I polish it or is shinny tooling gel coat polished enough as is?

I’m really happy it came out as decent as it did. This being my second mold ever made.

#2

I found that squirting a little high pressure air from a compressor really helps :slight_smile:

#3

Or pour water down it and hydropump it off.

#4

Oops… i majorly edited my post guys… maybe you will be kind enough to read it again :slight_smile: I was able to remove the heel guard plug, but it chipped the gel coat in a couple small places.

#5

I’ve wondered the same thing myself… it must be near impossible to mix up even say 10mls of gelcoat (which would still be too much), as that would require 0.1mls of hardner. Assuming you’ve got a 3ml eyedropper, you could probably give it a go, then just brush some into the hole, cure, sand.

I am quickly learning that you shouldn’t go too crazy buffing the wax off the plug :smiley:

#6

Buffing wax too vigourously leads to lots of problems that can be easily avoided!

The main reason for waxing a mould or plug is to apply a layer of wax, which will result in parts releasing without difficulty.

Seems to me that a lot of beginners think that the purpose of the wax is bring a high shine to the surface, and this is what leads to excessive buffing, and often poor release.

#7

if you’ve got a chip, mix up some epoxy and profil up to a thick liquid and apply it like you would body filler. Sand and your done.

#8

Fixing is easy. After cleaning VERY WELL the mold, just mix up more gelcoat, and squish on. You can control the sag by using some tape, and clay as dams (or flashbreaker if you have it)

Cleaning. Well, PVA is water soluble, so hot soapy water I would guess.

Polishing. If it’s as shiney as you like…go for it. If you are cutting out the clay section in the middle, then use your own judgement, but if you are keeping the guards solid, then yeah, you will want to work on the part of the mold where the clay was. :slight_smile:

#9

just fyi, dont ever use clay for such a big area like that. 1, clay has a shitty surface and your mold will NOT come out good. make a aluminum tape / poster board backing in those holes. its what i do to my heals.

#10

Yep, that was me!

When you say ‘lots’ of problems, could you elaborate on that?

Riff42, making dams out of clay, that’s a cunning plan! I like it!

#11

Yeah, i wondered about using the clay the way i did in the middle “cut outs” of the heel guards. I actually did use cardboard in those cut outs, then lightly covered the cardboard in clay to provide a barier against the gel coat. I’ll try and refine, using your idea for the next set of heel guards. I think another idea may have been to use Bondo body filler to fill in the cut outs on the plugs. I bent one of the heel guards removing it from the mold LOL.

I wasn’t actually going for the no cut out carbon fiber heel gaurds. I just wanted to duplicate the originals. I will cut out those openings with a drill and Dremel tools.

I’m going to make another style of heel guard mold here in a couple weeks, for my own bike.

I’ll try the tape or clay method and gel coat to fix the mold. Live and learn, right :slight_smile:

#12

I find mineral spirits will remove clay residue well (after the pva has been removed with water). Also, automotive “wax and grese remover” work well. I wouldn’t recommend acetone as it can dull the surface, especially on a new mould.
What brand of wax are you using, Fastr?

#13

PartAll #2

I just remembered a company’s products that i like… www.southernpolyurethanes.com

They sell a waterborne automotive cleaner that removes wax and grease and other debris. www.bakerpbe.com sells the SPI line of products. They also sell a ton of other supplies, some related, some not.