# Will fiberglass resin stick to cardboard OK?



## iScream

So I want to build two or three very crude enclosures, just to test my midrange and tweeters in different positions before really installing them. I'm using a 4" mid so the volume probably needs to be less than a liter. 

I'm thinking about just using cardboard, or a big sheet of that thick paper product they sell everywhere for kids crafts and stuff like that. I could cut to shape then glue up an enclosure with the volume I need, then just brush one layer of resin over it to seal and keep it from flexing much.

Anyone see a problem with this? Will the resin stick well to paper/cardboard?

Any other suggestions for going about this?

Thanks for any tips.


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## minbari

I have never had a problem with it sticking to cardboard. just make sure you prop it up with something. the cardboard will soak through and get mushy and sag.


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## req

sure. it will work. i went to michaels and got some cardboard 'bins' with caps on them and resin'd them for a test setup once.

you could also use tuppawear or something like that. if its gotta be a specific shape, then cardboard would be fine because you can cut\tape it together for a crude enclosure.


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## req

i would say - stick to uncoated and non-printed-on cardboard or thick paper. even get some chicken wire and form it to a rough shape, put a cardboard baffle on there for the speaker to drop into, wrap it in cloth and then epoxy the whole thing. that and it would be good enough for testing.


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## SPLEclipse

I use old moving boxes to protect my patio floor when I'm doing a fiberglass project, and I can attest that it will stick with no problem. I've also never had it soak all the way through, in fact the bigger problem will be that it won't soak through enough to prevent delamination problems. Give it a shot on a test piece to see if it will hold up without turning into a brittle mess.

Another option is to use PVC and end caps for the enclosure.


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## iScream

Thanks guys. Between my internet service being down for four days and searching for some midbass drivers I let this thread just sit here without participating.

I've got a couple cardboard baffles cut out for the mids and tweeters but I haven't tried to form the enclosures yet. I stopped by Home Depot to get some resin but it seemed expensive there so I'm gonna check NAPA and online. I want to try molding a subwoofer enclosure some day so I would like to get enough up front to do that.

I like the PVC suggestion too, if I can find the right diameter.


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## SPLEclipse

iScream said:


> Thanks guys. Between my internet service being down for four days and searching for some midbass drivers I let this thread just sit here without participating.
> 
> I've got a couple cardboard baffles cut out for the mids and tweeters but I haven't tried to form the enclosures yet. I stopped by Home Depot to get some resin but it seemed expensive there so I'm gonna check NAPA and online. I want to try molding a subwoofer enclosure some day so I would like to get enough up front to do that.
> 
> I like the PVC suggestion too, if I can find the right diameter.


Wal-Mart has quarts for about $14. Keep an eye out for Advance Auto Parts coupons, some of them are 40-50% off, and you can order resin through their website for pretty cheap. Not the best resin ever, but good enough.


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## iScream

SPLEclipse said:


> Wal-Mart has quarts for about $14. Keep an eye out for Advance Auto Parts coupons, some of them are 40-50% off, and you can order resin through their website for pretty cheap. Not the best resin ever, but good enough.


Thanks. I think it was about that price at Home Depot so maybe I'll just grab a quart for this and worry about getting more when I'm actually starting a subwoofer enclosure.


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## thehatedguy

That resin is junk.

Go to US Composites and get the EB General Purpose resin for $25 a gallon or spend a $30 and get the 435 resin.


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## iScream

I just typed up a paragraph but managed to lose it. Thanks for the info on the resin. I already bought a quart of Bondo brand but I'll order some of the better stuff for doing the real enclosures.


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## iScream

I have another question about new layups sticking to fully cured sections. I actually grew up with an auto body shop in my backyard. That's what my dad did for a living and he always had a couple jobs going on in the shop at home which he worked on outside his day job at the dealership. So, I was working fiberglass and bondo by the time I was a teenager and painting cars when I was 16. I haven't done it since I was about 22 though, almost 20 years ago.

I would like to mold a few sets of enclosure backs for my door at the same time, then join a front section later to make a sealed box out of it. Mostly so I can switch to a slightly larger mid later if I end up not liking the Scan Speak 10F for some reason, without having to build a completely new enclosure.

I think I should be able to layup a front section and have it bond just fine, as long as I rough up the cured glass with some course sandpaper. But it has been 20 years since I worked with fiberglass so I thought I would check.

I posted some pictures of what I'm up to in my build log.


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