[Milehighguy]

Yes, I had also thought of the DIY bed liners, and have shopped around a little looking at those. It's one option if a professional job is too expensive and if I don't go the bondo route.

[BradJudy]

You might be able to use that epoxy garage floor stuff.  It might be a pain on a curved surface though.

[bubba966]

You might be able to use that epoxy garage floor stuff.  It might be a pain on a curved surface though.

It would be a pain on a curved surface. Having down a dozen or so garages with the epoxy paint I can tell you that it wouldn't work very well if trying to do the inside of a barrel.

Also having a lot of experience with Bondo I can tell you that it'd be a huge pain in the ass to do the inside of a barrel. Not to mention that you'd need a couple of gallons. You'd also have to get a few extra tubes of hardener so that it would set up fast enough so as not to sag too much and not stay where you put it.

To get the Bondo to not sag too much you'd need to mix it so that it's set in under a minute & damn near fully hardened in 5 minutes.

That's a lot of mixing as well as a lot of $ for Bondo & extra cream hardener tubes.

I'd go the DIY truck bed liner route first.

Though better yet I'd line the barrel with Dynamat Extreme. That'd be rather easy to do. Wouldn't be too spendy either if you got one of the big "bulk pack" boxes of it off of eBay.

[Milehighguy]

Thank you for your input. It's good to get advise from someone who has some experience with these materials.

[RAW]

Jack.
I use the line spray at least once a week and believe me it is just paint not a sealer.I highly recommend not to use it for sealing the barrel.

Ok
Go to Wal-Mart (cheapest)
Purchase the large can of Bondo.1 Gallon.

Lay the barrel on it side and spread the bondo on the bottom and around the side up about 1/4 of the wall.This will not drop down at all.

The best way tomake it stiff with out using fiber glass.




I am sure on the line spray  




These are all for one customer.
Smaller cabinets with wings are for test cabinets for the large line array I am doing for him.
12 Accuton mids 9 G1 ribbons and these sit on top of 4 TC 12" on each side and last the large 18" NorthCreek subs are in these monster cabinets.

All of these cabinets were laminated MDF and birch plywood.
After I recieved them half assembled from the cnc shop (no our work) these cabinets sat for 48hrs and MDF shrunk so bad all over we had to let them sit for 3 months.The cracks the first few days spread over 20 inchs and some 1/4" width.

After letting them sit for a long 3-4 months inside we started the repair process.
From the outside first.
One side at a time we had to sand the cabinet(remember these large cabinets are 3.25" thick in spots) 46" tall 26" width and 32" depth.Not light at all.Well over 380lbs each cabinet.

As we did each side we needed to sand all the uneven MDF to a smooth as we could then bondo.

These cabinets after bondo then required a clading of 1/4" MDF to have a true smooth surface.

Only used 4 gallons of bondo to repair all the mis fit panels,ect.

Yes Jack I think this will work the best.
Like i said to a small amount at a time,do what will lay bondo flat on the inside then rotate.
Bondo will only need 10 mintes to set to the point you can roll that barrel.
Then reapply.
You can do all the bondo in less than 1hr to fill the inside smooth.

Also remember these barrels had liquid in them!!!!
Make sure they have dried 100% or you will have more cracking.
As well the liquid makes the barrels seal as the wood swells

All the best.

[Milehighguy]

Al
Thank you for taking the time to post all those details. One thing I wanted to clarify. I will be using a new barrel that has never had liquid in it. The place I'm getting it from says that it is made of pre-dried wood, and that these barrels are used to make musical drums, and they have not so far had problems with shrinkage or rattling with the drums. Of course, a subwoofer is going to stress the barrels more than using it for a drum would. One good thing is that a passive radiator design will not have the type of pressures that a sealed design would have. Again, thank you for sharing your knowledge and experience.

And thanks to you and Danny for making the RA8's!! They impress me every day when I turn them on and hear new details in songs, and the big, deep, and focused sound stage.

[RAW]

Welcome Jack.
Enjoy the RA8
And all the best with the Barrel sub

[Milehighguy]

I guess that I should add that it may be confusing that I'm talking about 2 different SuBarrel projects. One with a new 20 gallon (2.67 liter) barrel and the GR12 driver and PR, and a larger used whiskey barrel with a 15 adire tempest driver. And , yes I did experience shrinkage with the used barrel after sitting in the dry Colorado air. That one will definetly need treatment.

[mpm32]

I would think that fiberglassing the inside of the barrels would be easy.  Spread in some resin, lay in some mat.  Do a couple of layers, doesn't need to be pretty.

[jbandpc]

You could consider the stuff they use nowadays between the foundation and framing of houses.  It's like thick, wide, black, rubber tape.  From my understanding, they put it on the foundation and after the house is framed, they peel off the remaining backing and press it onto the sheathing or house wrap.  The same stuff, or something similar, is used for roofing around corners.  There is some similar looking stuff that is used for 'water features' to put under the rocks that keeps the water from disappearing into the ground.  (I don't think it has the adhesize)

Another product I've bought at Home Depot or Lowes (but haven't gotten around to using yet) is called "Plasti Dip".  (I have the spray-on type)
http://www.plastidip.com/consumer/products.html
I was thinking of spraying that inside my 5 cubic foot sealed Tempest sub.

[Milehighguy]

I appreciate everybodys suggestions. I will probably go with something that contributes to the strength and ridgidity of the barrel, like bondo or fiberglass or a thick layer of professionally applied bed liner. I'm leaning to the bondo, and I'm also thinking of spacing lots of screws inside the barrel that are sticking out of the wood maybe 1/4 inch or so. That way, the bondo would be more firmly attached to the barrel, and it would guarantee that I get a thick and uniform layer of bondo. When the screw heads are covered, I will know that the bondo is at least 1/4 inch thick.

The other thing is that I have to ask you all to be patient with this project, because my work schedule doesn't leave much free time. I probably won't even get the barrel out of the box until next week.

[jbandpc]

The other thing is that I have to ask you all to be patient with this project

No... we're going to need something on our desks by the end of the week.