[F-FT] Sealing grains

I've used one on SU loads but w/o "vacuum". I thought it might deform the grains. I tried asking AT about this but, I don't think they quite got what I was asking. Maybe someone else has knowledge on this...?

Stones

I haven't but it sounds like a good idea to me.

I've often wondered how igniters manage to rust inside a factory sealed pack. The ones I've seen do that were at least 10 years old but the packs were still sealed, you could just see through the plastic that they had rusted. The engines were fine but I threw the igniters away.

Randy

"David Erbas-White" wrote

This is a pretty common practice with KNSU/SB/etc

I wouldn't worry about it. Not only is the heating wire not all that hot, you can't get it in contact with the grains, anyway.

-Kevin

I've never seen packages that were vaccuum sealed, so there's air in there, with whatever moisture it contains.

Most (if not all) of these packages are not air-tight anyway. Some air slowly leaks through, much like how air leaks out of a balloon over time.

-Kevin

Igniters, matches and propellant contain oxidizers, "rust" is a result of oxidization. It's likely they "rusted" themselves.

IMO naked grains are pretty hard to light anyway.

Been doing it that way for years. It works great. Once stored a bag of Estes motors for 12 years that way. All motors performed perfect.

Ted Novak TRA#5512 IEAS#75

A vacuum is overkill. Aerotech does not vacuum their motors. They just seal them.

You can buy a pretty good bag sealer for about $60. You could probably buy a cheap one for resealing reloads occasionally for a lot less. Check Ebay.

I successfully flew some M1315 reloads that sat out in my garage over the winter unsealed still loaded in the cases. The only thing I did was unscrew the end closures a little bit to relieve the pressure.

Brian Elfert

I assume you're talking about "Solar" ignitors. I've found LOTS of them pre-rusted through, especially the ones in the sealed replacement ignitor packs that you can't see before you buy. For what they charge for them, you should take all the defective ones, save them up, and return them for replacement under their warranty.

Bob Kaplow NAR # 18L TRA # "Impeach the TRA BoD" >>> To reply, remove the TRABoD!

I've got a bunch of 1970 +/- a year vintage Estes motors still in the blue mailing tubes. They still perform fine. In fact I flew some this summer at NARAM, and if not for a stupid mistake would have taken a second place with one.

Bob Kaplow NAR # 18L TRA # "Impeach the TRA BoD" >>> To reply, remove the TRABoD!

please describe ?

the rest of us can learn from it.

Perhaps a little first hand info may help you make your decision...

I use one to seal all the liquids that I ship in my business. Each seal requires that I flatten the bag over the seal bar (i.e. the "wire") with my bare hands, and I quite often seal a 1/2 dozen bags in a row. Having used it about 25 times a day for 3 years now, I have never even noticed that it was warm from use. To be fair, I have dialed mine down to just enough to seal a 3mil bag without any folds to maximize the wire life. (2.5 out of 10. Folds/overlaps will not seal unless I crank it up or hit it twice in row). Even so, whatever amount of energy is imparted it is so small that the heat appears to be dissipated in the melting of the bag. At least, enough of it is dissipated that I never once thought that being a heat strip until this thread came up.

I'd certainly investigate it yourself before enagaging in in any behavior that may be risky. But, if you are looking for a quality sealer that will hold up to years of use and a source for bags, I recommend uline.com A link to the sealer is here:

Philip P.S. If anyone can recommend a cheap source (new or used) for an inductive cap sealer I sure could use one.

Rust = oxidation. Pyrogen = Fuel and oxidizer.

Need I say more?

Philip

2 stage rocket, booster stage spit the motor in staging. I use an unconventional design, and should have put a tiny motor block at the BOTTOM end of the booster. Or used a LOT more tape...

Bob Kaplow NAR # 18L TRA # "Impeach the TRA BoD" >>> To reply, remove the TRABoD!