Things that Epoxy WONT stick to

As a few of you know, I am in the middle of building my 29mm CF scratch build (video build). I have my mandrel and made the fiberglass part of the tube last night. I wrapped the tube in this plastic stuff i found and prayed that the glass would slip off. I know, BAD IDEA. The tube isnt coming off and I'm afraid that Ive ruined my mandrel.
Here's my question: what plastic easily peels off of fiberglass? In the past I have used ziploc bags (which actually work great for making fiberglass sheets) and wax paper (which didnt work at all :eyeroll It needs to not scrunch up like plastic wrap, but NOT to thick that it wont wrap well. I have heard the Mylar works perfectly for the job but the only place i know that sells mylar (PET) film is McMaster-Carr and I would rather not pay shipping. Does anyone know of something that i could pick up at home depot or ace that would work equally well?

BTW: My mandrel is wooden so using a mold release would be out of the equation.

Thanks,

Alex

Mylar - 5 mil.
I bought this:
https://www.tapplastics.com/shop/product.php?pid=255&

a little cheaper:
https://www.rplastics.com/clear-polyester-sheets-film-rolls.html

A couple rolls of plumbers teflon tape, the wide stuff?

I know that it won't stick to the nozzles or fins of the Estes Rubicon. Nothing will stick to that plastic.

Parchment paper!!!! I use it for everything to wrapping tubes, to peel ply.

Eat said:

Parchment paper!!!! I use it for everything to wrapping tubes, to peel ply.

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I know when I mix propellant, I use this on my tray I pack grains on. The binder used does not stick to it. It is delicate like wax paper though.

For those that don't know, this is in the super market next to the wax paper. Silicone instead of wax?

Eat said:

Parchment paper!!!! I use it for everything to wrapping tubes, to peel ply.

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Gracias Señor. I'll pick some up tomorrow!
I always get parchment paper and way paper confused!

Alex

Aksrockets said:

Gracias Señor. I'll pick some up tomorrow!
I always get parchment paper and wax paper confused!

Alex

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su bienvenida

epoxy won't stick to packing tape. Potatoe chip bags are made of mylar. How much mylar do you need? Are you sure your layup is 'glued' to your mandrel? Or is it stuck for other reasons? Other reasons could be mandrel not the some OD from end to end, tapered or low spots in the mandrel. If there is any tape holding your release film to the mandrel under your layup...your screwed. Only tape release film to mandrel at the very ends..where you can remove it after part is layed up. Right after I get a body tube layed up I un-tape the release film and make sure the piece wants to start coming off the manrels. I keep checking it about every 15 minutes..working it off more and more. I use mostly motor cases for manrels and it's amazing how tapered or out of round motor case can be. Trying to remove the part while the epoxy is still green lets you know how well things are going to turn out. When I say 'remove'..I should be saying freeing up.

Tony

Aksrockets said:

My mandrel is wooden so using a mold release would be out of the equation.Alex

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You can shellac the wooden mandrel, then wax it or apply release agent. If your stuff is still stuck on the mandrel, try putting it in the freezer overnight. I might release with a sharp blow when cold.

Second the parchment paper. I've used it extensively. easy to obtain!

Ditto on the parchment paper. CA also will not stick to it (I use a layer around mandrels when making CA coated tubes). Downside is that NOTHING wants to stick to parchment paper - getting it to STAY around the mandrel is interesting (So far, using masking tape all the way around so the masking tape sticks to itself is the only thing I've found to work.) At least with CA, wax paper will give up a coating of wax when you remove the piece from the mandrel.

Can someone give me a link to the product?
Quickly!!!

Alex

Aksrockets said:

Can someone give me a link to the product?
Quickly!!!

Alex

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You mean this?


https://www.walmart.com/ip/Reynolds-Parchment-Paper-Genuine-Parchment-Paper-30-sf/11027109

Greg

GregGleason said:

You mean this?

https://www.walmart.com/ip/Reynolds-Parchment-Paper-Genuine-Parchment-Paper-30-sf/11027109

Greg

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Parchment paper is great stuff. I use it for many things, but covering a mandrel is not one of them.

Jim

I've bought mylar emergency blankets at Kmart to make streamers from. They are only a couple of bucks for a large sheet. I'm pretty sure I've also seen rolls of thin plastic gift wrap at almost any card store. Party City has tons of plastic table cloths, which seem to be pretty slippery. I think you still should sand, seal and wax the heck out of your wooden mandrel, to make it as slippery as possible.

Be careful with the parchment paper -- some of it has micro perforations in it, some does not.

Before doing a large layup, if you're not sure of the particular brand you have, test it on a smaller piece, first.

Are you using anything (shrink tape, vaccuum bag, etc) on compress the layup? If so, you might want to reconsider the wooden mandrel, as it, too, will compress a little bit, which will make it that much harder to remove afterwards.

-Kevin

Epoxy will not stick to packing tape. I usually use the clear stuff, doubt it would stick to the brown plastic tape.

Marc

Graduator said:

I've bought mylar emergency blankets at Kmart to make streamers from. They are only a couple of bucks for a large sheet. I'm pretty sure I've also seen rolls of thin plastic gift wrap at almost any card store. Party City has tons of plastic table cloths, which seem to be pretty slippery. I think you still should sand, seal and wax the heck out of your wooden mandrel, to make it as slippery as possible.

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If I were in school, I'd just "procure" a couple of transparencies. They still have those .... right? Well, Kinko's then ...

Jim

How about Duralar???

The majority of us who do layups for FAI style rockets just use Crown Mold Release. It's a wax that can be heated up in order to slide your finished airframe off the mandrel.

I've use parchment paper before and sometimes there's a tiny amount of soak thru which can make it a little difficult to pull off the mandrel, but it's probably your cheapest and most available option.

Fe Dude said:

How about Duralar???

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From https://www.grafixarts.com/home_article_pages/General_Frequently_Asked_Questions

Does Grafix offer Mylar?
Yes. Mylar refers to polyester film, which Grafix offers under the tradename Dura-Lar. Mylar is DuPont’s tradename for polyester film.

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Greg

Murphy says anything you want it to stick to.