I was trying to build a Wildman mini kit according to these excellent instructions:
https://www.rocketryforum.com/threads/wildman-wild-child-darkstar-minis-all-glass-are-here.16370/
Sadly I didn't read over them very well, because I missed the part about refrigerating part A and B before starting work. Of course after mixing parts A and B, the expansion started immediately, and I scrambled to fill my can. I should have just aborted but I didn't, and now I have learned the hard way how not to foam a fincan. I think I've also learned that I do not like foam, but I might give it a second chance with the refrigerator trick. There are 3 fins, and 1/3 of the fincan is good, 1/3 is okay and 1/3 is not good, err uh I mean optimized to reduce weight.
1. The 'weight optimized' segment has a void taking up about 2/3 of the space of where foam should be. It is sealed with foam on top centering ring and out the back, but there is a huge gap in the middle, I can see it through the fiberglass wall. I guess I have to drill a small hole to fill the void? Out of curiosity how much weaker would the rocket be without filling that void? Not that I plan on leaving it that way.
2. The second chamber is about 95% full. There is one bubble. Anything to worry about?
3. Any tips on getting the foam off the outside of the BT without scratching the fiberglass? I had a few dribbles down the side.
Also, I noticed the foam (PML) has an expiration date of 2/21. That's less than a year from now. Did I get an old batch or does it normally have a short shelf life?
https://www.rocketryforum.com/threads/wildman-wild-child-darkstar-minis-all-glass-are-here.16370/
Sadly I didn't read over them very well, because I missed the part about refrigerating part A and B before starting work. Of course after mixing parts A and B, the expansion started immediately, and I scrambled to fill my can. I should have just aborted but I didn't, and now I have learned the hard way how not to foam a fincan. I think I've also learned that I do not like foam, but I might give it a second chance with the refrigerator trick. There are 3 fins, and 1/3 of the fincan is good, 1/3 is okay and 1/3 is not good, err uh I mean optimized to reduce weight.
1. The 'weight optimized' segment has a void taking up about 2/3 of the space of where foam should be. It is sealed with foam on top centering ring and out the back, but there is a huge gap in the middle, I can see it through the fiberglass wall. I guess I have to drill a small hole to fill the void? Out of curiosity how much weaker would the rocket be without filling that void? Not that I plan on leaving it that way.
2. The second chamber is about 95% full. There is one bubble. Anything to worry about?
3. Any tips on getting the foam off the outside of the BT without scratching the fiberglass? I had a few dribbles down the side.
Also, I noticed the foam (PML) has an expiration date of 2/21. That's less than a year from now. Did I get an old batch or does it normally have a short shelf life?