Tube hardening

[carson]

Anybody use thinned epoxy to harden the tubes on low powered rockets?
Or tried using an auto epoxy primer?
That epoxy primer is as hard as nails.
Seems it would create a nice hard surface to work with.
Epoxy primer is like sanding a rock

 

[mwiggins367]

Epoxy, even thinned, would add a lot of weight. What is the purpose of the hardening? If you are hardening to use bigger motors, then the extra weight is not that big a deal. If you are hardening for extra durability, then the extra weight would really effect performance.

Thinned yellow glue will help harden as well and it is not as heavy.

 

[powderburner]

I often swab a little CA around the inside surface of the ends of cardboard BT. This is to make them a little more durable when inserting motors, or when placing the NC into the front. It also gives a teeny bit more protection from the "Estes dent" (although a well-placed whack is still going to do some damage).

One other place that might need some reinforcement is the portion of BT just ahead of the MMT. The high temp and heat loads from the ejection flash can do some damage over time, so if you want your (sport flier) rocket to last a bit longer you can swab some extra white (or yellow) glue around the inside of the cardboard BT.

Other than that I usually don't try to add much to a cardboard BT, at least in the way of reinforcement. For getting a good finish, you are going to have to sand it smooth and straight, and plain old filler is much easier to sand than epoxy...

 

[BobCox]

Epoxy doesn't add much strength. Many rocketeers reinforce their tubes and fins with fiberglass, which is a combination of glass fibers and epoxy resin. The strength comes from the glass; the epoxy just holds it in place. Properly applied fiberglass will use as little resin as possible. The primary purpose of vacuum-bagging and heat-shrink tubing is to squeeze out the excess resin.

As powderburning already pointed out, soaking the inside of each tube end with thin CA adds strength without much weight.

 

[Stymye]

sounds like a quasi-phenolic tube without the heat and pressure

 

[falingtrea]

Have you tried Viagra? :rotflol:

 

[powderburner]

Re: the little blue pill

I don't think my hardened arteries can take it

 

[Gillard]

i nearly always go for washing the inside of model rocketry tubes with thin CA glue, adds next to no mass and stops the ends getting tatty.
better still, buy good quality tubes in the first place.

 

[fox_racing_guy]

I use Minwax Sanding Sealer, I apply it at the same time as I'm sealing my fins and it does seem to stiffen up the cardboard tubes.