I have finally decided on the dimensions and style of sub that I going to build. I have done some research and seen many people seem to use some sort of epoxy when glueing their MDF joints together. I have done several wood working projects in the past using MDF, including speaker boxes, but wanted to know if this "epoxy" really is superior to regular wood glue or any other adhesives. I have used regular wood glue in the past with no problems. I usually sealed the inside with liquid nails or just plain silicone. I assume this works just fine--it seemed to. I have recently become a pretty big fan of gorrilla glue and was planning on using it on my upcoming projects. I have at least 3, possibly 4, sub projects that I have told myself I am going to complete this winter and I want to buy a large quantity of adhesive once as opposed to buying several small bottles.

So, what adhesive do you use and why?

I use Tightbond II wood glue. As an added precaution, I also use it to make sure the joints are air tight. No silicone or liquid nails.

-Robert

I have used all of these.

Epoxy is the strongest and the most expensive it is also a bit messy to work with.I use it on critical joints were I may not be able to clamp things tightly. It also has some gap filling properties.

Wood Glue(Yellow) is fine as long as the joint can be clamped very tightly together
or its strength will be comprimised.Nice and easy to clean up excess with wet rag.

I have used Gorilla glue to join pieces that may have a slight gap because it expands and fills in the void nicely.It gives a strong bond and excess is easy to sand away after it cures .It is a bit expensive and I only use it when my need the gap filling to make up for sloppy cutting of panels.

I've used 'em all and for MDF, plywood and wood I find that nothing beats plain old yellow glue. With even modest clamping, or the use of screws to draw the joint, it is stronger than MDF and is as strong or stronger than the bond between plys in plywood. The other versions such as Titebond II give you some more choices such a water resistance or longer open time.

You might want the longer open time, or a different temp range for application and curing, but water resistance in most locations is not needed.

Titebond and its cousins are so strong that with a clean cut you can make permanant miter joints just using clear packing tape to hold the joint while the glue sets.

Yellow glues, unlike epoxy, are subject to slow failure or joint creep, if the joint is subjected to pressure along the joint, but this shouldn't be a problem in speaker boxes. Epoxies can fail from a sharp blow along the joint.

Gorilla Glue has its uses and I use it, but not for normal wood or MDF joinery. It does fill gaps to some extent, but not with very much strength. For example it is my chioce for repairing an old plane handle, because Rosewood difficult to glue using yellow glues.

As with some others I find that a bead of yellow glue along interior joints seems to work fine for sealing. A well fitted joint in MDF, actually should not need any additional sealant, if the glue is throughly spread, but it can't hurt.

I use Tightbond III. Works well. Have tried Gorilla glue several times and been pissed every time. I just don't like it, and it is a real pain to clean off your hands. Lots of people talk about how it expands to fill gaps - but it fills it with an open cell foam, same as an expandable foam. That isn't worth much.


Like I said, I like Tightbond II and III.

Depends on what it is you're gluing. For me I use three or four: Yellow for wood-to-wood joints, Plumbers glue for ABS pipe to wood (ports), Lepage PL series 900 for other surfaces like the inside of Sonotube which can have a waxy coating on it. I've found PL to be excellent for surfaces that are out of the ordinary.

Hot melt glue is excellent also if you are doing wood-to-wood with groves, but you have to allow extra clearance for the thickness of the glue itself.

Best,
Mark

I have used Gorilla glue to join pieces that may have a slight gap because it expands and fills in the void nicely.It gives a strong bond and excess is easy to sand away after it cures .It is a bit expensive and I only use it when my need the gap filling to make up for sloppy cutting of panels.
I'm with The Rocket on this one. I used to use Gorilla Glue, but since I got a table saw I don't need its gap-filling properties and so Titebond or Elmer's Wood Glue works just as well and is hella easier to work with.

Depends on what it is you're gluing. For me I use three or four: Yellow for wood-to-wood joints, Plumbers glue for ABS pipe to wood (ports), Lepage PL series 900 for other surfaces like the inside of Sonotube which can have a waxy coating on it. I've found PL to be excellent for surfaces that are out of the ordinary.

Hot melt glue is excellent also if you are doing wood-to-wood with groves, but you have to allow extra clearance for the thickness of the glue itself.

Best,
Mark

Mark, can you please be more specific about the "Plumbers glue" thing (contents etc.), as I live in Norway and probably don't have access to the same brands as you.

I'm trying to find out what to use for the PVC/wood gluing myself.

Its actually plastic pipe glue - yellow in colour, very stinky, and available off the shelf of any hardware store selling plumbing products. The glue actually melts the plastic to form the bond. Here's a link to examples:

http://www.azpartsmaster.com/shopazp/Plastic%20Pipe%20Glue.html

Best,
Mark

If I need gap filling, I use an epoxy. I always get the longest setting time I can find (60 or 90 minutes).

Also, if I do not know what to use two join two different materials, I just use the epoxy.

For MDF to MDF, I use some of the gallon of original Tightbond I got for <$15 (and a lot of clamps).

Building a 6 cu ft sub encloser.Construction will be 1" MDF and 1/2" oak veneered MDF,hence 1.5" wall thickness throughout.

What's the best glue and the proper method for gluing these rather large panels?

I use Titebond III. It works very well for most MDF joints. However, I've found that I do get some joint creep on my top and bottom caps with that glue. I can sand the joint until it's glassy smooth and you can't even feel it by running your fingers over it, but wait a couple of days and expansion/contraction of the cap will make the Titebond joint slide a bit with respect to the walls it's glued to. This wouldn't be enough to cause a problem in a veneered cabinet, but it might very well mar a paint finish. I'm in the process of trying to come up with a solution. I've got various tests underway to see what solves the problem the best, but I think I'll probably end up using epoxy on the caps. In any case, I think this joint creep demonstrates that, contrary to popular belief, Titebond is NOT stronger than the MDF. If it was, the MDF would be flexing/tearing instead of the glue joint creeping.

Building a 6 cu ft sub encloser.Construction will be 1" MDF and 1/2" oak veneered MDF,hence 1.5" wall thickness throughout.

What's the best glue and the proper method for gluing these rather large panels?

Regular yellow glue will work just fine to laminate two sheets like these. I use a notched trowel to spread glue evenly over one of the sheets, then clamp the other onto it.

I used whie PVA glue for bonding mdf, liquid nails where there are gaps or sealing issues, and epoxy for critical bracing to improve rigidity.

I love Gorilla Glue. Once you know to spread it thinly, you appreciate the 4 hour cure time. It uses water as a catalyst, so you lightly spray the opposing side of the joint using a spray bottle. You leave the expansion on the inside seam and scrape off the excess with a knife on the outside.

I use Titebond for my speaker projects for the MDF joints, and I've used it for veneering even though it isn't really recommended. To attach the ports I use Household Goop or Plumbers Goop. I also apply silicone to the inside of the box joints to seal them, but it probably isn't necessary.

I've used Goop to also glue the bigger xover caps and inductors to the board to keep them in place, especially if the board is mounted on the side. It also prevents rattle.

Whatever works.