The problem with putty is that it doesn't whet out to the body and fin since
it's so viscous. I prefer to use a 60min epoxy (longer set times generally mean
a stronger bonding epoxy) filled with microspheres to thicken it slightly and
then put the body on a rotisserie horizontally to keep the epoxy from sagging.
I get very nice fin root fillets this way. I should add that I will pin the
fins in place with a couple of spots of super glue to hold the fins in place
while the epoxy cures.
Ken
On Jun 7, 2016, at 11:38 AM, Alexander Jones wrote:
Adrian, it looks like you can get this stuff at some home depot stores,
apparently in the plumbing section. On another note, I've had okay results
with the loc-tite brand stuff that's also available off the shelf at HD (I
tend to go for the stuff that's wet applicable, which might explain my
success with it re: the brittle issue), but it really depends how much stress
you're planning to put on the joint. If it's minimum diameter or you're
otherwise expecting super-high accelerations and mach+ speeds, I'd reevaluate
it....if you're staying below mach and you're using a robust fin attachment
like TTW, you should be fine. Also, all the putties are actually A+B, just
some of them combine it into one "log" of putty, with the hardener in the
outside layer, usually the colored layer, then the epoxy is the core and is
usually white or at least lighter-colored....you use a plastic knife or
something to chop off a little section of the log and just knead it together
until it's homogeneous.
On Tue, Jun 7, 2016 at 11:02 AM, Adrian P. Bailey <adrian@xxxxxxxxxxxxxxx>
wrote:
Thanks Alexander and Mike!
I can’t get the Amazon order to work (and have been using Prime for years) so
they may not have it in stock for same day. They do have A+B epoxy putty.
It’s for fin fillets and what I’ve read is that some putty is too brittle and
the fillets break off.
From: roc-chat-bounce@xxxxxxxxxxxxx [mailto:roc-chat-bounce@xxxxxxxxxxxxx] On ;
Behalf Of Alexander Jones
Sent: Tuesday, June 7, 2016 9:44 AM
To: roc-chat@xxxxxxxxxxxxx
Subject: [roc-chat] Re: Epoxy putty
Adrian, looks like you're in luck, there's a rocketry forum post where a guy
gives a brief review of this exact product:
http://www.rocketryforum.com/showthread.php?74822-Rectorseal-EP-400-Epoxy-Putty-Works-Great!
On Tue, Jun 7, 2016 at 9:41 AM, Adrian P. Bailey <adrian@xxxxxxxxxxxxxxx>
wrote:
Has anyone used Rectorseal Ep-400 Epoxy Putty, or have other recommendations?
I’m looking for something that Amazon can deliver today… ;)
