MDF and Gorilla Glue

[Consul]

I tried doing a search for this, but found literally tens of thousands of threads that contain all the different keywords I tried.

I'm looking to build my first set of speakers (a transmission line using small Tang-Band full-rangers), and I've run into some confusion about what glues will and won't work with MDF. So, to cut to the chase, I already have a bottle of Gorilla Glue from other projects around the house. Will that work? Do I need to go buy something else?

Thank you for the help.

[zobsky]

You could just use regular yellow glue (such as titebond) . Gorilla glue (and PU glues in general) expand a bit when curing (useful for filling voids) but make sure the pieces are clamped well (to prevent them from slipping/shifting) .

Don't ask me how I know this

[chrismercurio]

I prefer TiteBond and pretty much any professional wood glue to gorilla glue. Water cleanup and a beautiful bond without the expansion problems of polyurethane glue are my reasons. I have read tests on Gorilla vs Titebond and with Titebond, the wood will fail before the joint will and the opposite is true of the polyurethane.

I used Gorilla Glue on an outdoor project last summer and was not impressed. If you do use it, make sure NONE of it gets on your skin.

[Consul]

I was specifically told that water-based glues will not work on MDF because they won't soak into the material, and that a solvent-based glue is required. I have some Titebond laying around somewhere, too, and if you all think that works just fine, then that's more than good enough for me.

[chrismercurio]

Just about anything will soak into mdf. Titebond is fine.

C

[Consul]

Great, thanks!

[richie00boy]

When you talk of Titebond not being PU, that's just the Original and II versions isn't it.

[chrismercurio]

I like this as well as it offers the workability and cleanup of I and II but is also waterproof (if you need that).

[Teh]

A: Titebond is NOT waterproof. Its darn good wood glue but its not waterproof. Try it on your deck once, you'll find out in the first rain strom.

B: Polyurethane glue is moisture activated. In other words you need to wet down both surfaces to get a maximum bond. By the way it is quite waterproof. I've used it on my redwood deck. Regardless, it is an absolutely fabulous bonding agent. Remember it foams and when hard it is almost impervious to anything. It does sand quite well though. It really is superb stuff. So, clean it up along the way (paint thinner).

Heck, the only thing that is actually waterproof are "some" epoxies. Even Gelcoats (fiberglass boats) are NOT waterPROOF. Actually almost nothing is.

The use you are speaking of is the biggest issue. If you are gluing joints, PVA glues are excellent. Elmers, Titebond and numerous others. Frankly, they're all quite similar. All are stronger than the wood itself.

If you're edge gluing anything I'd be inclined to use Urethane glues. It is just impervious to anything and everything. Especially if you're going to be machining it.

Regardless of your choice all of your joints should be physically clamped and nothing should be without countersunk screws. Even done perfectly (which really is very easy) all joints should be sealed with something on the interior of the enclosure. Hot glue is superb if your finger can handle it. So is silicone. That's just excellent. Actually Vulcom Urethane caulking is a pretty darn good choice as well. It NEVER deteriorates, never.

Fill all of your screw holes with water putty or something like that (plastic wood filler). Use a wide blade knife (maybe 6") to spread it consistently. Mix it thin and use two-three coats. Sand them flush and DON'T oversand. Use a machine sander that doesn't require much pressure, like a Bosche or hand sand the final. Don't go lower than 100 grit. All of your veneers, regardless of type depend on the validity of your surface preparation. Clean, clean, clean! Use something like denatured alcohal.

Good luck!

[Consul]

I'm going to be using the "glue and screw" method for this one. Thank you all for the help!