Working with Large Cardboard Tubes

[Dave A]

I have wrapped 9" cardboard tubes several times. The interior of the tubes are real pourous.
Have any of you coated the insides with them, like with thinning epoxy or sanding sealer?
Would any other pre-treatment help prior to bonding to bulkplates, couples, etc.?

 

[Steve Shannon]

I have wrapped 9" cardboard tubes several times. The interior of the tubes are real pourous.
Have any of you coated the insides with them, like with thinning epoxy or sanding sealer?
Would any other pre-treatment help prior to bonding to bulkplates, couples, etc.?

People used to wrap cardboard tubes and then throw them in the pool to dissolve the cardboard, leaving just the strong fiberglass matrix. Get rid of the weak, coarse cardboard.

 

[Dave A]

People used to wrap cardboard tubes and then throw them in the pool to dissolve the cardboard, leaving just the strong fiberglass matrix. Get rid of the weak, coarse cardboard.

Not looking to do that. The booster is already wrapped with some layers bonded to the tube. If one were to plan your method you'd wrap the tube with a release film before the glass. Plus the couplers are already sized to the ID of the cardboard tubes.
Just looking to see if a light sealer of some kind to the inside had be used by someone.

 

[Banzai88]

Add one good coat of sanding sealer and it'll seal it right up. Poor man's phenolic. The cardboard will drink it in. Works well. USE SPARINGLY, you don't want to saturate the cardboard or you'll get delam. Practice on a cut off piece first, you'll figure it out in 5 minutes or less.

This is what I use: https://www.lowes.com/pd/Minwax-Water-based-Sanding-Sealer-Actual-Net-Contents-32-fl-oz/999914203

After it's thoroughly dry, hit any interface points (where a nose cone or av bay has to slide) with a quick buff of 400grit paper and it's done. Smooth as silk.

 

[Dave A]

Add one good coat of sanding sealer and it'll seal it right up. Poor man's phenolic. The cardboard will drink it in. Works well. USE SPARINGLY, you don't want to saturate the cardboard or you'll get delam. Practice on a cut off piece first, you'll figure it out in 5 minutes or less.

This is what I use: https://www.lowes.com/pd/Minwax-Water-based-Sanding-Sealer-Actual-Net-Contents-32-fl-oz/999914203

After it's thoroughly dry, hit any interface points (where a nose cone or av bay has to slide) with a quick buff of 400grit paper and it's done. Smooth as silk.

That's what thought, glad to confirm, Thanks, Dave