We couldn’t resist with Serge and did another session to release the tube of the mandrel. Following the plan we started with filling the tube with ice to check if it’s going to do the job.
It is not that obvious on those pictures above, but it seems to be cracking, it did nothing.
We’ve resented to the plan B – using a brute force and cut it off.
It didn’t go well and took us probably 10 minutes to do so and while we made it, our Aluminium tube suffered some serious scratches.
On the other hand, holding our first tube attempt was pretty satisfying and it clearly has some parameters we are looking for. We agreed that if we’ll be able to take it off the mold properly, it is likely that it’s going to do the job.
Anyway, it was time to check at least some parameters.
As you can see on pictures above, we ended up very close to producing one meter tube weighing 135g. When we take weight of CF tape used ~ 94g it comes with 70:30 CF to resin ratio – which is apparently very good. Next stage would be vacuum bagging where it is possible to reach 75:25, still very close!
In preparation for our next stage we made another trip to ACME Composites and finally got our Resin and HTG Hardener.
Thinking about how to get ready for another go, we formed a new plan:
1/ Test 150C curing with single CF strip – two wraps and check if we’ll be able to take it away when mold cools down
2/ If it won’t we’ll use ice
3/ If it’s going to work out we’ll continue and will try to do 30 cm strip keeping enough tape to potentially continue
4/ Assuming that 3/ worked out – we’ll try to continue and do another 30 cm and so on
5/ In case we won’t be able to continue, or that joint won’t work we’ll cut it of and do another – separate 30cm tube and try to join them together with overlap
6/ If everything fails we have a plan B – Chris came with a plan to split our tube in half to create a gap or space which could be used to release the tube when curing finished