Old 09-21-2003, 03:10 AM   #1
Posts: n/a

I'm building one of the sonotube subs in the next couple days, and I was going to fiberglass the inside of the tube so that it's a little more rigid to prevent flexing and resonance, but the inside of the tube has an anti-stick coating on it that allows it to be peeled off easily after concrete has cured. So if I was to fiberglass on top of this, would the FG shrink away from the sonotube, leaving me with another tube of fiberglass inside of the cardboard sonotube?
Old 09-21-2003, 03:23 AM   #2
Posts: n/a

I guess that would depend on what the coating is made of. I don't think the fiber glass will shrink too much. The only problem I see is the fiber glass and standard resin probably won't bond too well to that surface leaving you with at least a non-bonded fiberglass tube inside the tube. Typically if the the resin can't soak into a substance, its not going to stick very well to it.
Old 09-21-2003, 03:27 AM   #3
Posts: n/a

yeah, that's what I'm worrying about... I might have to sand the coating off
Old 09-21-2003, 03:51 AM   #4
Posts: n/a

I hate being a stickler, but fiberglass doesn't shrink. Resin can and does, depending on what type you're using. Polyester resin tends to shrink more than epoxy during cure, but that's not necessarily the case for all resins. Check the data sheet for whatever resin you plan on using.

As far as the non-stick coating on the concrete tube, why not get in there with some sandpaper and scuff it up? That should help your layup stick.
Old 09-21-2003, 03:03 PM   #5
Senior Member
Join Date: Aug 2000
Location: Lake Havasu, AZ USA
Posts: 1,307

Why not fiberglass around the outside of the tube?

If you glass inside the tube, yes the fiberglass is going to shrink away from it.

'Glassing around the outside solves that problem, plus it's so much easier.. just wrap fiber around the tube and wet it out.
Mike Pipes
MPipes is offline  

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

All times are GMT -4. The time now is 07:01 PM.

Powered by vBulletin® Version 3.6.8
Copyright ©2000 - 2015, Jelsoft Enterprises Ltd.