Tube Mandrels?

Scrapmaster87 said:

What is everyone using for tube mandrels and where are you getting them? Also what are you using as a release film/layup to get the tube off?

I'm just now getting back into the hobby, i traded rockets for robots when I started high school 18 years ago. My dad being a plumber, we had lots of copper and steel pipe for mandrels. We were making kevlar-fiberglass tubes when I stopped flying. Those builds we're never finished, but I'm homing to get them flying after I get my level 1.

I see mylar? being used a lot as a release film on the mandrel? What else works? Our schedule that we had worked started with waxing the mandrel, then about 3 layers of craft paper, followed by about 2 layers of a black trash bag. We would finish the layup with several right wraps of cling-wrap.

I'm designing a ~2.5" upscale of an Estes thunderhawk that my dad and I built in the mid '90's. Sadly the original no longer exists, but I have the scale data. I have some 7781 8.9oz e-glass on the way and am eyeing up some 2.5" stainless tube for the mandrel:. https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.com/ulk/itm/142032300389

I also have porous PTFE coated fiberglass coming for peel-ply.

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prfesser said:

I make spiral-wound tubes from kraft paper tape, and wrap the mandrel with silicone-treated backing paper from labels. The backing paper from large peel-and-stick floor tiles works nicely. I kept all the backing paper from the 18" square tiles we used on the kitchen floor. I haven't used it with epoxy but it should work at least as well as wax paper.

Best -- Terry

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