I just finished my first mold for a DLG pod fuse. The mold was made from West Systems epoxy.

I was thinking of using polyester resin to make some test parts because I want a quick turn around time while learning how to join the parts in the mold before I start making "real" parts. I intend to make real parts from epoxy.

Question: Will I do any harm to the epoxy mold by using polyester resin to make a few experimental parts?

Thanks,

Russ

I suggest just buying a pint of fast hardner.
Mike

Using wax and PVA I've made a jillion parts of both epoxy and polyester in molds made from polyester with no problem. I'm not sure about the reverse?? Well waxed and PVA'ed I'd think it would work fine....O.L.

You will do no harm to the epoxy as long as you use mold release wax. Epoxy bonds terribly to polyester and visa versa. It's really ideal for your purpose in fact.

Have fun!

Originally Posted by isoarthenland

I just finished my first mold for a DLG pod fuse. The mold was made from West Systems epoxy.

I was thinking of using polyester resin to make some test parts because I want a quick turn around time while learning how to join the parts in the mold before I start making "real" parts. I intend to make real parts from epoxy.

Question: Will I do any harm to the epoxy mold by using polyester resin to make a few experimental parts?

Thanks,

Russ

Russ well done on your first mold.

Save your money - as you intend on epoxy as your final part- practice with epoxy. Polyester does handle a little differently so you would benefit from epoxy practice anyway. So little epoxy goes into a DLG pod if the product doesn't work you are not wasting much anyway. A "hot/warm box" will speed turnaround time.

Who knows you may end up with a keeper first go

cheers jeff
On topic .. wax and pva = no harm from polyester.

Thanks for the info and opinions. I think I'll go ahead and use epoxy. You never know, like Jeff said, I may end up with a keeper the first time.

Here's a couple of pictures.

Russ

as jeff said, just go with the epoxy.. you'll probably use less than 50g's on that mold so it's not like it's going to break the bank

What are you using for the boom?

The boom is tapered, 30" long, 5/8" at the big end, 5/16" at the small end. When I moved to Utah, the local club (Intermountain Silent Flyers) were starting a club project to build some DLG's and one of the members got us a deal on a bunch of booms. I don't recall where they came from.

Nice! Are you going to use a silicone plug?

How are you going to do your seams? I notice that you have no openings in your mold. You might want to consider sanding down your alignment nubs. When they are tall like that, it makes it difficult to "slide" the halves together and get the tape or wet halves to mesh together.

You've got a nice looking mold!

Adam

Ward, thanks...no silicone plugs this time. I've read up on them and they look cool, but not this time around. The goal with this mold was to learn how to do it, and end up with a sport DLG that could be replicated for a club project.

Adam, thanks to you too...


I had already made a hatch mold from the plug. Today I cut the back end of the mold where the boom fits so there is a nice round open hole there now. I also cut the mold half's where the hatch will go, so there is a nice wide opening there. I'll be epoxying a small 1/4" strip of hatch material around where the hatch goes so I'll end up with a ridge where the hatch fits (I hope) I intend to do a wet seam. I can't recall the technical name but the seams will be part of the layup of each side, not separate strips of cloth.

I don't have a picture of the cut up mold...I left the camera at the New Years Eve party with the kids/grandkids...

Happy New Year all!

Russ

Russ, good luck with your first part.

Adam