Gluing and Clamping

[wintermute]

When you are going to Glue and clamp something, make sure you have more clamps that you could possibly think you would need.

It's been four years since I made my speaker boxes (had a bit of a break) and this afternoon I went to glue the rear baffle on to one of the boxes after much sanding to get a good fit. I had forgotten how much of a nightmare gluing can be!. The baffle slipped around all over the place once it had the lubrication of the glue, and would not go where I wanted it!

Not only did I need the to hold the surfaces being glued together tight, I also needed clamps which were not applying pressure to the glue face, to hold the work in place in the horizontal plane!

So whilst I first thought I needed 8 clamps, In reallity Ideally I should have had 12 holding it in place front to back (my box has two partitions so needs some extra clamps) and another 6 to keep the baffle in the right place on the horizontal plane. That's 10 more than the initial 8 that I thought I would need!!

Also It is a good idea to position the baffle in place and then tighten up the locator clamps (not the ones applying the pressure) first so that when you tighten down the ones that hold the glued surfaces together it doesn't slip around. There should be something between your clamps and the sides so that they don't get glued to the surface when the glue seeps out between the seams.

I've attached an image of my clamps as per this afternoons effort. Hopefully all will be ok, but I really could have done with another 4-6 clamps!!

Tony.

[AndrewT]

glue and screw

[wintermute]

yep that too AndrewT I did for the other parts of the box If you look at the end you will see the six screw holes, but had some problems with the MDF splitting (probably didn't use a big enough drill bit). Didn't think it was an option for my front baffle as it will be chamfered though I guess I could have removed the screws post gluing, before routing...

Tony.

[Ed LaFontaine]

A few grains of salt (or sand) will diminish the tendency to slide.

[AndrewT]

A square batten screwed on from the inside of the corners solves the exposed screw head and the splitting problems. This method is extremely strong and very resistant to shock/drop loading.

[Glowbug]

but had some problems with the MDF splitting (probably didn't use a big enough drill bit).

Predrill, predrill, predrill

[wintermute]

thanks guys. I'll have to take note of these suggestions with my next cabinets.

Ed, the salt I might try, the sand, I'd be worried it would affect my seal!

Glowbug I did predrill, just not big enough!! tried to match the drill bit to the size of the shank of the screw, but obviously that wasn't enough.

AndrewT that is a good idea, provided front baffle is done first would work nicely, and the rear baffle can just be screwed as per normal (ensuring the screw holes are big enough)

Tony.