Quik-Tube, Glass Mandrel or Glassed Body Tube?

Some 8'' concrete forms waiting in the garage to be turned into an upscaled scratch built version of my L1 rocket.

All tubes will fit real nice together with just a veil layer of glass or so on them but will be fairly heavy as the cardboard tubes themselves are about a pound per foot minus whatever the veil layer might weigh.

Now, I have been thinking about a veil layer over the tubes, then a mat layer over that (for strength) then another surface veil layer of glass. Then soak/erode with pressure washer or by whatever means the cardboard tubes away leaving just glass body tubes.

Locally available Bondo glass (6~9oz?) cloth and mat is what I'll be using unless I find better local source.

All to be done with ProLine Epoxy not Polyester BTW.

Objective is to keep it light enough for a 54mm K805 + 3x 38mm J??? peripherals but strong enough for a low end 75mm "M' someday.

I know this has been done before, I just haven't found a good write up on it.

Anybody ever hosed the cardboard out of glassed tubes with any success? Caveats? Gotchas?

Thanks in advance for any helpful input you might have.

Here's an R&D version of the rocket I have in mind.
Negate all weights and altitudes for obvious reasons.

View attachment C III R n D.rkt

Don't use Bondo mat with an epoxy resin -- you won't get the strength you expect. There's a binder in the mat that holds the fibers together, which is specifically designed to dissolve in a polyester resin. Without it dissolving, you won't properly wet out the fibers.

There are mats out there designed to work with epoxy resins, but I don't know off the top of my head who carries them.

Removing the cardboard isn't a huge deal; I've seen it done, never done it myself. Just soak it in a tub of water until it's soggy, then pull it out.

-Kevin

troj said:

Don't use Bondo mat with an epoxy resin -- you won't get the strength you expect. There's a binder in the mat that holds the fibers together, which is specifically designed to dissolve in a polyester resin. Without it dissolving, you won't properly wet out the fibers.

There are mats out there designed to work with epoxy resins, but I don't know off the top of my head who carries them.

Removing the cardboard isn't a huge deal; I've seen it done, never done it myself. Just soak it in a tub of water until it's soggy, then pull it out.

-Kevin

Click to expand...

Wow! Now that's a gotcha I never saw coming. I think I'll look around a bit and see if I can find a better selection of fiberglass around here.

I'm glad I asked.

Thanks Kevin.

check these guys out...top quality glass verry tight weave.
https://www.fiberglasssite.com
their glass works well with poly resin and epoxy.

troj said:

Don't use Bondo mat with an epoxy resin -- you won't get the strength you expect. There's a binder in the mat that holds the fibers together, which is specifically designed to dissolve in a polyester resin. Without it dissolving, you won't properly wet out the fibers.

There are mats out there designed to work with epoxy resins, but I don't know off the top of my head who carries them.

Removing the cardboard isn't a huge deal; I've seen it done, never done it myself. Just soak it in a tub of water until it's soggy, then pull it out.

-Kevin

Click to expand...

Excellent info, I'm glad you shared on the bondo mat

This is a link to a different method but there is a lot of good information.

https://www.vatsaas.org/rtv/construction/tubeform/tubeform.aspx