Next Project: Arc 40 CBT Array

[Kevin K.]

Do you have some sort of dust collection set up on the CNC?

At work we typically cut vacuum-formed plastic on the machines which only generates plastic pellets, not near as messy. For MDF, I would normally be holding the end of a shop vac tube close to the cuts and it catches most of the dust, but holding the camera and the shop vac tube for the video would have been tough so I just let it make the mdf rooster tails in this instance.

[Kevin K.]

Need some advise here fellas. Reached the point where the enclosures are ready to be closed up. When I attach the last panel it has to seal against the edge with the arrows, otherwise the enclosure leaks. Clamping the last panel isn't going to work so I am adding blocks where I can and will shoot screws to hold it until the glue cures. Once the panel is secured, it is blind and I wont be able to see if it mated well to that edge. Thinking gorilla glue since it expands would be the best bet but want to see if you guys agree or suggest something else. Thanks.

[Sydney]

Have you ruled out the various means of clamping irregular shapes?
Is it possible to transfer the joint lines to the remaining side piece?

[Navy Guy]

Need some advise here fellas. Reached the point where the enclosures are ready to be closed up. When I attach the last panel it has to seal against the edge with the arrows, otherwise the enclosure leaks. Clamping the last panel isn't going to work so I am adding blocks where I can and will shoot screws to hold it until the glue cures. Once the panel is secured, it is blind and I wont be able to see if it mated well to that edge. Thinking gorilla glue since it expands would be the best bet but want to see if you guys agree or suggest something else. Thanks.

You might try something thick like PL Premium adhesive. I've heard Gorilla Glue can expand enough to push things around sometimes, but I have no experience using either, so take this with a grain of salt.

[Kevin K.]

Have you ruled out the various means of clamping irregular shapes?
Is it possible to transfer the joint lines to the remaining side piece?

I played around with several different clamping methods but didn't find any I felt super confident in. I'm certainly open to suggestions.

Yes, the joint line could be transferred to the remaining side piece, what did you have in mind?

[Sydney]

Various "ideas":
Strap clamps / Flex strap pieces / Clamp culls that provide a perpendicular face for standard clamps to work against.

Pilot holes could be set on the side piece to screw/pull into the frame while glue sets.
Or the line could be a brad nail guide.
( FWIW I've used numerous urethane based glues. To a certain degree expansion can be controlled. )

[Kevin K.]

Various "ideas":
Strap clamps / Flex strap pieces / Clamp culls that provide a perpendicular face for standard clamps to work against.

Pilot holes could be set on the side piece to screw/pull into the frame while glue sets.
Or the line could be a brad nail guide.
( FWIW I've used numerous urethane based glues. To a certain degree expansion can be controlled. )

Will be using a clamp cull towards the top rear, no choice. Considered the straps but was concerned about damaging the veneer on the baffles, maybe a piece of foam would protect it? Will be using pilot holes to screw the panel to the additional blocks mentioned. Didn't feel screws could be shot into the edges of the 1/2" MDF without splitting it, this was the reason for the additional blocks.

What do you think of using the urethane glue on the edge with the arrows and regular titebond everywhere else? The urethane would be able to expand left and right and shouldn't cause bulging since it would have a place to escape.

[Kevin K.]

You might try something thick like PL Premium adhesive. I've heard Gorilla Glue can expand enough to push things around sometimes, but I have no experience using either, so take this with a grain of salt.

I've seen the PL Premium mentioned a couple of times here on the forum. Do you know what the pro's or cons are vs the Gorilla urethane glue?

[Sydney]

I guessing your tolerances are very tight and a dry fit of the piece confirms no gaps...
Standard Urethane ( aka Gorilla ) would be sufficient.
I also thought that attaching several small wood blocks/strips to the interior frame ( to screw into ) would avoid using the MDF and possible splitting.
Closed Cell foam ( like pipe insulation ) can be used as clamp cushions.

[Wolf]

I pretty much only use Gorria-Grue (, I like saying it that way) anymore. I used to use Elmer's Ultimate as it wasn't as thick, but it's harder to source in larger bottles now than GG.
As long as you use enough, it can fill the gaps, but if you want maximum filling glue, the PL is likely better. Don't use it sparingly. Run a good bead down the edge and clamp. Since Poly glue requires moisture to expand and bond, if it's dry In your shop, you should likely moisten the mating surfaces with a damp sponge before applying the glue. The little amount used will not really affect the MDF.

Oh- and DON'T wear clothes you care anything about. It will not wash out. If I get it on my fingers, I like to keep a small container of sawdust handy to absorb it. This way you don't have to go wash or adhere your other things to your hand.

Later,
Wolf

[drab]

Cut the panel into two pieces so you can visually ensure the chamber is sealed? Use something thicker like a soft rubber/putty or perhaps silicone on just that joint? Never done anything like this so these are just WAG's here.

[Kevin K.]

I pretty much only use Gorria-Grue (, I like saying it that way) anymore. I used to use Elmer's Ultimate as it wasn't as thick, but it's harder to source in larger bottles now than GG.
As long as you use enough, it can fill the gaps, but if you want maximum filling glue, the PL is likely better. Don't use it sparingly. Run a good bead down the edge and clamp. Since Poly glue requires moisture to expand and bond, if it's dry In your shop, you should likely moisten the mating surfaces with a damp sponge before applying the glue. The little amount used will not really affect the MDF.

Oh- and DON'T wear clothes you care anything about. It will not wash out. If I get it on my fingers, I like to keep a small container of sawdust handy to absorb it. This way you don't have to go wash or adhere your other things to your hand.

Later,
Wolf

Worst case scenario for the gaps would be about a razor blade thickness. Knowing this, would you suggest the urethane or the PL Premium? If urethane, would it be better to wet the surfaces with a damp sponge before applying the glue or mist the glue with a spray bottle right before applying the panel, have you tried it with a spray bottle?

[Kevin K.]

Cut the panel into two pieces so you can visually ensure the chamber is sealed? Use something thicker like a soft rubber/putty or perhaps silicone on just that joint? Never done anything like this so these are just WAG's here.

I like the idea of cutting the panel into two pieces to visually ensure it's sealed but feel that could lead to problems after the veneer is applied and the seam might telegraph.

[Wolf]

The GG should likely work for that sized gap. Both are polyurethane glues. I like using a sponge, as a spray bottle will wet a lot more surface area than you may want to in application. I know of others using spray bottles, but I've not preferred that method. I use a small blue scotch-brite sponge I've had in the garage for years for this purpose alone. You just have to get it moist, not soaked. I would make a sample first to test your methods.

Later,
Wolf

[jhollander]

I've used the both the gorilla glue and PL polyurethane in tubes. I prefer the PL in tubes as it's thicker and you can get a decent bead on the MDF edges. I've also used a spray bottle to add moisture when I did a glue up in the winter. My only tip would be to clamp/ screw/ hold for a day or two. The poly glues don't seem to get hold strength as fast as the yellow glues.