Expanding foam in the fin can

[Jase]

When filling a fin can with expanding foam, is it better to pour the foam in and let it expand out of the body tube and then grind it down to where it needs to be?

Or is it better to pour the foam and as it begins to expand, put the aft centering ring on to "trap" the foam in the body tube?

Curious mind needs to know.

 

[PGerringer]

Like Dick said in a different thread, definitely take your time and go in small batchs. The first time I used expanded foam was in a nosecone. I mixed a little and it filled up half, so I mixed it again this time to much cause the foam practically exploded out of the nosecone. One thing I do disagree with Dick on, though, he said it tends to expand out, well I say be prepared for it to run down the side like the 1970's version of The Blob. It makes an utter mess. Easy to clean off a rocket and countertop though buy sanding.

Oh, and to answer your question. I usually don't restrict the foam, too much pressure and you can bust open seems you didn't know you had. Enjoy.