MDF speaker build

[gychang]

I plan to build a small speaker and put on a THICK veneer. I have build several speakers with plywood and never used the veneer.

I have a circular saw, and the usual tools including a router. Any good place to start learning about how to work with MDF?, where is a good website for veneer purchase?

thanks,

gychang

[Knottscott]

Sorry I don't know of any good sites for MDF and veneer tips, but I can tell you that MDF works quite nicely. It is however, extremely dusty and isn't good for your health so I'd advise a dust mask. If your married, your wife or SO won't appreciate it getting tracked into the house either! ...it's pretty silty.

Also be aware that MDF isn't great for holding with screws. I use them as reinforcement and to hold a glued joint together until the glue dries.

Good luck with your project!

[drumpriest]

Commercial veneer sources typically have 1/32" thick veneers or so. You can get some sheet 2 ply veneer from Rockler, but each sheet is still very thin. I saw my own veneer to get them at 1/16" for marquetry, and have not found a source for thicker veneers.

[LCHIEN]

isn't "thick veneer" an oxymoron?
Veneers are thin by definition.

[Alex Franke]

Ditto on the MDF warning -- use a respirator if possible -- and goggles, of course. Cutting it releases urea formaldehyde. Also, there's a LOT of glue in MDF, so it can dull your blades pretty quickly. Keey an eye our for burning or other signs of dull blades.

MDF is prone to splitting, also. If you're using screws, always drill pilot holes and try to keep the screws in about an inch from the edge, if possible.

I know you want to vaneer, but in case you decide to paint instead, it can be tricky because the MDF soaks in a lot of paint unevenly, especially on the edges. I get good results by covering the edges in drywall compound, then sanding, oil-based priming (all surfaces to seal in the urea formaldehyde), sanding again, then painting.

That said, it does work very well and you can do some nice details that you can't do with plywood. I'd probably try to use plywood if possible, though. Plywood also holds screws better.

[BigguyZ]

Well I build my set of speakers with MDF. I'd go a step further than other people have noted and recomend a respirator when working with it- it's gets everywhere, stays airborne for a long while after it's machined- especially with a router- and is made with chemicals like fermeldehyde which is toxic.

As far as working with it- at the time I build my set I didn't have a TS. I used a factory edge from an MDF panel and a flush trim bit to do any rip cuts. To make the boxes, I didn't use any fasteners. I simply used butt joints and plenty of Tightbond II glue. I didn't have any issues with the strength of the box at all- I found that they were plenty strong. If you have a concern about using butt joints, you can to a rabbeted joint. I didn't want to use fasteners because I rounded over the edges of the enclosures with a 1 1/4" roundover bit. The larger roundover on the edge helps dispersion. For veneer, I used the stuff that woodcraft carried. I like the paper-backed veneer to work with, since it's less likely to crack. To apply, I used the iron on yellow glue method.

[gychang]

Well I build my set of speakers with MDF. I'd go a step further than other people have noted and recomend a respirator when working with it.
For veneer, I used the stuff that woodcraft carried. I like the paper-backed veneer to work with, since it's less likely to crack. To apply, I used the iron on yellow glue method.

Well, I better stay with plywood (have touch of allergies...), I want to try some veneering the box, I will look into woodcraft, is there a video or instruction on the net re: iron on yellow glue? I know iron edging but need to veneer the whole box. thanks.

gychang

[jziegler]

If you want iron on, you can get sheets of veneer with an iron on adhesive already on the backing. I saw some of Lowes recently, although only in a couple of woods (Oak, maple, cherry maybe). Other sources will have it as well.

There seems to be some debate over the longevity of the yellow glue iron on.

For the MDF, is it possible for you to do the work outside? That way you don't get the dust in your workshop/house and it disapates more quickly. MDF makes a better speakers than plywood from what I've read.

Jim

[BigguyZ]

As Jim said, you really don't want to use plywood, or at least not alone. Wood has a natural resonance- meaning that certain freuqncies will cause the wood to naturally vibrate. Now with a good plywood that's minimized, but MDF has no resonance b/c it's a bunch of small particles glued into flat panels. MDF really is a better way to go.

As far as veneering goes, it's simple. I get a small foam roller and apply an even coat of glue on both the veneer and the cabinet. Then, wait until the glues are just a little tacky, but not totally dry. Then position the veneer where you want it on the enclosure. Take an iron (wrapped with a pillow case if you don't want to ruin it) and run it over the surface. I think the cotton setting is what you want it on. The iron will actually melt the glue, bonding the two surfaces together. Work your way from one side the the other, and you're done. Make sure there aren't any bubbles as you go- take the time to work them out before you get too far along.

[BigguyZ]

http://www.oakwoodveneer.com/tips/ironon.doc

Here's a link to a doc from a website that walks you through it.

[gychang]

If you want iron on, you can get sheets of veneer with an iron on adhesive already on the backing. I saw some of Lowes recently, although only in a couple of woods (Oak, maple, cherry maybe). Other sources will have it as well.

There seems to be some debate over the longevity of the yellow glue iron on.

For the MDF, is it possible for you to do the work outside? That way you don't get the dust in your workshop/house and it disapates more quickly. MDF makes a better speakers than plywood from what I've read.

Jim

Jim, live in duplex housing, so not ideal to work outside, will check out Lowes.

gychang

[gychang]

As far as veneering goes, it's simple. I get a small foam roller and apply an even coat of glue on both the veneer and the cabinet. Then, wait until the glues are just a little tacky, but not totally dry. Then position the veneer where you want it on the enclosure. Take an iron (wrapped with a pillow case if you don't want to ruin it) and run it over the surface. I think the cotton setting is what you want it on. The iron will actually melt the glue, bonding the two surfaces together. Work your way from one side the the other, and you're done. Make sure there aren't any bubbles as you go- take the time to work them out before you get too far along.

"Yellow woodworker's glue", is there a brandname etc. I will go to HomeDepot or Lowes.

thanks for all the help from everyone.

gychang

[Alex Franke]

"Yellow woodworker's glue", is there a brandname etc.

Titebond I, II, or III. I usually use II.

III is darker and more water resistant. I is least strong (but still VERY strong), and not suitable for anyting outdoors (not water resistant). II is a good compromise

[gimpy]

Google veneering and you should probably get some good hits. There are several places on the net to buy veneer (that I have read about, have never bought any). I think there are a couple of sites that have good veneering tutorials. I thought I had a couple bookmarked, but can't find them. It seems like one is something like Joewoodworking. Also, people recommend Tapeeze. I know there are more. E-bay has veneer, also.

Frank

[JamesDad]

If you can find one issue #104 of Fine Woodworking, Febuary 1994 has an artical ("A guide to medium density fiberboard" by Jim Hayden) that you might find useful. It covers the different types and applications. It also the fasteners and glues to ase and the joinery techniques that work well.
One thing I found out is that all MDF is not equal. The MDF that I saw at Suwanee Lumber Co. where I bought some curly maple looks like better quality than the stuff I bought at HD. It seemed to be harder throughout its thickness as if HD's imported MDF isn't formed under as high of pressure.