what's on your mandrel?

[AP aroma]

I posted this on the "Scratch built" forum but now I'm thinking it is better suited to the "Techniques" forum.

I have had trouble getting the Mylar removed inside an airframe layup of fiberglass. I use two layers of 2mil Mylar from Tap Plastics to separate the resin from the mandrel. I am careful to only apply masking tape to the ends of the Mylar as i am putting it on the mandrel. What do others use for this separating layer? Does anyone wax the Mylar to future help it release from the resin?

Thanks,
Jim

 

[jbr]

https://www.amazon.com/Mann-Release-Technologies-Ease-200/dp/B002YEBO1O

 

[Scrapmaster87]

I use parchment paper, but your upper limit is gonna be 4.5" (4" pipe). I'm gonna give reciept paper and packing tape a shot next. Filiment winding may be my next tool making project, x-winder has a tutorial on youtube using paper and tape.

 

[shockie]

I posted this on the "Scratch built" forum but now I'm thinking it is better suited to the "Techniques" forum.

I have had trouble getting the Mylar removed inside an airframe layup of fiberglass. I use two layers of 2mil Mylar from Tap Plastics to separate the resin from the mandrel. I am careful to only apply masking tape to the ends of the Mylar as i am putting it on the mandrel. What do others use for this separating layer? Does anyone wax the Mylar to future help it release from the resin?

Thanks,
Jim

How about some ptfe aka teflon film? Check out CS Hyde. Comes in various thicknesses.

 

[REK]

I use parchment paper, but your upper limit is gonna be 4.5" (4" pipe). I'm gonna give reciept paper and packing tape a shot next. Filiment winding may be my next tool making project, x-winder has a tutorial on youtube using paper and tape.

I would keep with the parchment paper and I recommend spiral wrapping it much like the tutorial for the paper and tape technique. If anything though I recommend not doing that as I have tried it and I have found it to most difficult to remove the finished part from the mandrel.

Use the parchment paper, it is better.

 

[prfesser]

Firefox carries 4" wide PTFE tape, 36 yards for $12. Almost nothing sticks to PTFE.

 

[G_T]

We used to use a very low temperature melting wax on mandrels. Spray it on liberally, outdoors. Make the part. Then, once the part is cured but not post-cured, submerge in hot water for a little bit and slide the part off.

Another thing we used at times was magnetic tape. Spiral wrap it. We used a spinning jig to make that easier. Use close to 50% overlap. Pulls off the inside of the part very easily when done, and can take a bit of heat for post cure. However, we used it on the outside for compression wrapping. The non-shiny part goes towards the epoxy. Yes, counter-intuitive.

Electric tape, just under 50% overlap, sticky side out. Wrap that around your mandrel.

Many ways to skin that cat.

BTW, it helps a great deal if your mandrel has a very slight taper to it. The longer the mandrel, the more that matters. Otherwise, a sliding removal can be difficult no matter what you do.

Gerald