Talk Composites - The Forum for Advanced Composites

Vacuum bagging my telescope tube mould

http://www.talkcomposites.com/Topic34690.aspx

By Robert72 - 1/26/2020 11:01:13 AM

I have included pictures of my telescope tube mould bagging attempt.  Currently struggling to hold a vacuum.  The setup is envelope bagged, using a single 5m length of bag material from EC to save on joins.  The bag goes through the inside of the tube then around the outside, with a single join at the end.....

Is there a better way of doing it?  I am asking because this is my second attempt with no success.  My first attempt was to line the inside and outside seperately.
The other end.....

The inside, vacuum pump end......

Also, the outside of my mould has internal corners that the bag struggles to close up to.  Should I eliminate these with a fillet?....

Thanks in advance for any help people.
By Robert72 - 1/26/2020 6:13:27 PM

 
f1rob - 1/26/2020 5:17:31 PM
I would say bag looks marginal on size 
Both diameter and lengh.
That's not to say you couldn't do it with the bag you have but just makes it more difficult !
If its a good bag and you haven't done anything silly the leaks in your tape, give yourself a bit longer bag to bring your tape out further so it's easier to work on.
Any bolts etc double breather
The bag will go in the sharp corners but you need plenty of spare,pull a partial vac then work your bag around the job dont try to push in to the corners when its fully vacuumed. 
Get a water sprayer an spray your bag
Makes it a LOT more supple 

Thanks for your reply f1rob.  The mould is 1.5m in length x 0.4m dia., and i am using all of a 5m bag. If anything it is too big diameter, but about right in length i think.  The end is partially tucked in, as i had it tucked in the mould for it to stand upright for infusion.  I think I am going to fillet the mould, look for any sharp points and cover the bolt ends as you say.  Then try again.