I'm becoming a bit of a convert to Gorilla glue. I know that it can be messy, but it has one redeeming feature that (so far) I've not found in any other adhesive. It expands with brilliant gap filling properties. This expansion can sometimes work against you, but a lot of problems can be overcome with careful use of masking tape /fluid. It works well on chipboard as it expands into the chip texture. It also glues other materials to wood. And it's damn strong.
I've invented
AMDF. This is Aluminised MDF which is a thick sheet of MDF that has a thin sheet (or sheets) of aluminium Gorilla glued to it. It gives you a thicker overall material to work with, and the aluminium provides the edge hardness for accurate layout and construction. They build the Dreamliner aircraft from composites like this. Not sure if they actually use MDF though...
I've invented
AMDF. This is Aluminised MDF which is a thick sheet of MDF that has a thin sheet (or sheets) of aluminium Gorilla glued to it. It gives you a thicker overall material to work with, and the aluminium provides the edge hardness for accurate layout and construction. They build the Dreamliner aircraft from composites like this. Not sure if they actually use MDF though...
Gorilla is one of the polyurethane adhesives on the market. I think they have a purpose, but they're not a panecea. Here's an interesting article which cuts through some of the marketing hype:
The Truth About Polyurethane Glue - Popular Woodworking Magazine
(don't miss the second page of the article)
The Truth About Polyurethane Glue - Popular Woodworking Magazine
(don't miss the second page of the article)
Dust in the workshop is nasty, regardless of the origin. I shudder when I think of what I used to breath in. I now have a large dust collector in the shop, with pre-fllter, connected to all my machines. I've also set up a sanding station with sanders connected to another vacuum with a 'Dust Deputy'. I also wear a dust mask when machining, and have an additional ceiling mounted dust filter to provide another level of dust elimination.
Please don't misunderstand me. I'm not suggesting that Gorilla is equivalent to epoxy. Not at all. I think though that it does fill a gap (get it?) between epoxies and PVA type adhesives. As your article suggests, 1mm gaps fill fine. 1mm is probably a bit of a stretch for a strong PVA joint. For example, gluing steel studs into MDF is an excellent use. They hold really well as the glue gets into the treads and then expands. Bonding a wide range of materials is also useful. Knobs onto rods, etc. It seems to really like MDF and chipboard, including the end grain if you can call it that.
I'll still keep a tube of the Araldite on the shelf though.
I'll still keep a tube of the Araldite on the shelf though.
I used 2 inch by 2 inch battons screwed to the mdf for about 30 years.
Just recently I started glueing and not screwing.
Just glueing means you have to be very accurate with your wood cutting or you get gaps.
Then once glued it needs clamping or weights put on the wood to hold t tight until the glue sets.
The glued joint will be stronger than the mdf you use so is very strong and reliable.
Just recently I started glueing and not screwing.
Just glueing means you have to be very accurate with your wood cutting or you get gaps.
Then once glued it needs clamping or weights put on the wood to hold t tight until the glue sets.
The glued joint will be stronger than the mdf you use so is very strong and reliable.
Would you mind expanding on what you mean here please? I use a lot of MDF and am always interested in wonderful new ideas.
I just use 2" by 2" lengths of wood along the edges to hold the box together.
I've worked in mock ups and prototypes for years, always used the urea glue on any wood type product. The time I tried some of the gorilla glue was when assembling a clothes drying rack, the pieces all fell out with little resistance after curing...
The one application where the foaming urethane works well is making lamination assemblies.
So if you want to make a curved cabinet, the gorilla glue would work pretty good for that.
There is a system of moisture cure urethane made by 3M that uses a heated dispenser, and works similar to the hot melt glue, however is much much stronger after a few hours. This system is used by some production speaker companies. The system costs around $1,500, is pneumatic, electric.
+1 on the mdf dust from routers, saws, my lungs are probably half full of that...
The one application where the foaming urethane works well is making lamination assemblies.
So if you want to make a curved cabinet, the gorilla glue would work pretty good for that.
There is a system of moisture cure urethane made by 3M that uses a heated dispenser, and works similar to the hot melt glue, however is much much stronger after a few hours. This system is used by some production speaker companies. The system costs around $1,500, is pneumatic, electric.
+1 on the mdf dust from routers, saws, my lungs are probably half full of that...
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Polyurethane glue fills gaps and is widely marketed in these days as a unique cure-for-all type of miracle glue, of course also more expensive. The joints are weaker than PVA, at least on what I have tested (Soudal and Henkel). As someone noted above - if the cuts are not perfect and clamps are not used, PVA will not produce a good bond. Fast clamps work on smaller stuff but for large loudspeakers mine (Irimo) don`t have the pressure needed so back to old school screw type clamps.
I've always screwed together PB, M and H DF using a DIY version of the Kreg 'pocket screw' system and whatever wood glue I had laying around; Elmer's, Titebond, etc., until PL400 construction tubes came along, since it's incredibly strong and thick enough to fill mildly questionable joints, but it's nasty stuff, so always use disposable gloves as it's a !@#$$%%%^ to get off skin without losing some.
If you have 'issues' with screws or just cheap like me and want to just use them as dirt cheap clamps, then just remove them after it dries and fill the holes with glue and/or dowels and/or if forced to use them on the exterior, then mix sawdust and glue to make a putty filler.
GM
If you have 'issues' with screws or just cheap like me and want to just use them as dirt cheap clamps, then just remove them after it dries and fill the holes with glue and/or dowels and/or if forced to use them on the exterior, then mix sawdust and glue to make a putty filler.
GM
I once tried to build an MDF enclosure using plain butt joints. The problem was that as MDF behaves like a multi-layer of very thin films, the top layer of the MDF sheet that is glued to the cut panel tends to peel off and split.
The simplest way to do a good MDF joint is to use mitre joints, so that no "finished" part of the panel receives any glue and stress.
Although MDF machines and trims nicely, the fact that it has fine dust that does no good makes me avoid it.
The simplest way to do a good MDF joint is to use mitre joints, so that no "finished" part of the panel receives any glue and stress.
Although MDF machines and trims nicely, the fact that it has fine dust that does no good makes me avoid it.
I will sometimes create more surface area by gluing cubes at the inside joints. In other applications that call for it glue strips of hardwood backing pieces. That anchors the screws well, they arent pulling out.
Clamp panels and line everything up then set some screws. This way I can easily true everything back up when Im ready for glue. Remove the screws and reuse them.
Clamp panels and line everything up then set some screws. This way I can easily true everything back up when Im ready for glue. Remove the screws and reuse them.
Do you recommend plywood for small enclosures? like 1 cubic foot, which is about a good size for 10" woofers and less. Want to reproduce a model I made, which is a cube about one 3f. Want to make it simple joining the pieces, so I am thinking using that material and a couple of #10-12 screws on every edge. However, will use MDF for the cover/baffle, which I found nice when spray painted, that piece receives 4 screws on the surface. All other sides will simply be carpeted.
I use plywood (Baltic Birch / ApplePly) for all my speaker builds of any size. Heavier duty subs might need more than a single layer of 15 or 18mm, but with appropriate bracing, battens as Cal suggested above, or dadoes, etc., you can build a sufficiently sturdy box for almost any application.
#8 lo-root (not drywall!) screws are more than adequate - and to repeat Cal's suggestion , cleats or battens along internal joints make for very strong construction using all simple butt joints. I recently built a pair of approx 1.25ft^3 sealed boxes for 9" bass drivers from single layer of 3/4" (18mm) BB, using butt joints and brad nails - the only screws involved are those mounting the drivers and terminal input cups
#8 lo-root (not drywall!) screws are more than adequate - and to repeat Cal's suggestion , cleats or battens along internal joints make for very strong construction using all simple butt joints. I recently built a pair of approx 1.25ft^3 sealed boxes for 9" bass drivers from single layer of 3/4" (18mm) BB, using butt joints and brad nails - the only screws involved are those mounting the drivers and terminal input cups
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I recently built cabinets using System Three epoxy in cartridges that have both parts in one tube and use a special tip to mix the epoxy as it is squeezed out. The cartridges use a standard caulking gun. I used the quick hardening variety and "clamped" the boxes for about 15 minutes with masking tape. Worked great, and let me get to the next step in the building process the same day rather than waiting a day for the glue to harden. I would use it again. Just make sure the cabinets are square while the epoxy is hardening, because it sets fast and there is no turning back.
Sure, but today's yellow cabinetmaking glues are quite sufficient for speaker construction, and many have very quick initial tack, with generally no more than a couple of hours required for safe handling between each clamping / nailing set-up.
Do this long enough, and you'll find your own favorite methods / materials - there's more than one way to skin a cat. Relax, pet owners, that's just a figure of speech.
Do this long enough, and you'll find your own favorite methods / materials - there's more than one way to skin a cat. Relax, pet owners, that's just a figure of speech.
I agree. I usually use Elmer's white or regular Titebond for cabinets. This was an experiment to see if using the fast setting epoxy would speed up the process. It did, but cleaning up afterwards took longer. All of the glues mentioned in this thread are more than strong enough for speaker cabinets without additional fasteners.
Its often said glue is glue. in the past Ive tried generic white glues some types you can find on the cheap in a dollar store perhaps. It looks the same and has a similar consistency so it isnt too far off for one to think, glue is glue after all. Its not and you might find out later on when something starts letting go on ya, often it pays to pay more . The yellow carpenters glue bonds much better depending what your gluing together.
The cheaper ones can bond the processed materials pretty well but when it comes to solid woods get the good yellow stuff. It might be because it contracts and expands differently, and has tighter pores. I cant say but I have had pieces let go after a short time when I used a cheaper glue.
One of the carpenters glue I like to use is made by Lepages. Ill use it on everything paper and wood related, cloth materials and leather.
The cheaper ones can bond the processed materials pretty well but when it comes to solid woods get the good yellow stuff. It might be because it contracts and expands differently, and has tighter pores. I cant say but I have had pieces let go after a short time when I used a cheaper glue.
One of the carpenters glue I like to use is made by Lepages. Ill use it on everything paper and wood related, cloth materials and leather.
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