Shrink wrap wrinkles

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#1

Hi All,

Has anyone any tips on avoiding wrinkles using shrink wrap on tapered tubes?

I’m making bike chainstays which are tapered along their length, when I wrap them in shrink wrap, I get a lot of wrinkles. If I do a straight tube I have no problems.

Thanks

#2

The tapered yacht masts I have seen are usually ok. Wrapped from the smaller end going towards the bigger end with a 19mm wide tape.

#3

I’m using a wider tape than that, so I’ll try a narrower tape and see how it goes. Thanks.

#4

And use smaller overlaps as well

#5

You can try heat shrink tubing rather than tape: http://www.shrinktape.com/products/heat-shrink-tubing/index.aspx

I’m not an expert for mandrel tubes, so I cannot vouch for it. Just a suggestion

#6

Interesting - Has anyone tried shrink tubing? I would imagine it could be difficult to get over fibres without disturbing the cloth, particularly if using wet lay-up, unless the shrinkage is massive I guess

#7

I’ve used it before. You can get 4:1 ratio heat shrink which gives you room to play. Big thing is to start from the middle and work out to the ends. Very common to use over braided sleeve. I haven’t used the Dunstone product, just normal no glue heat shrink.

#8

I would think you would want a perforated version to allow air/resin to evacuate as pressure increasing. However once again I have not been involved in much mandrel stuff in the past, just thinking theoretically here.

#9

With the 19mm wide tape I typically overlap it 2/3 so there is 3 layers and the final finish has the rib/edges 6mm apart.

For a thin laminate you can just overlap half, two layers.

Give it a reasonable tension as it goes on.

#10

Hi All,

Thinner shrink wrap and closer wraps did the trick. Thanks for all the advice!

#11

Nice job, did you manually wrap it?

#12

I did, until I discovered it was a pain, so I’m not doing it manually any more. It’s amazing what you can do with an electric drill and a few scraps of wood.