Paul Carmody Speedster Design

[Eppie]

That's real nice too. Love the grain in that Birch. Thanks for the extra info. I have used epoxy plenty of times and I'm more than familiar with getting it on my fingers. Varsol removes it too but I should get some denatured alcohol. I usually use Orange hand cleaner with pumice afterwards to remove chemical residue from my hands.

Don't seem to have the variety of supplies in Canada but I have some woodworking friends that should have a line on where to get the proper epoxy. See mostly LePages and the containers are not that large. I have a high pressure sprayer but would have to set up a booth in the garage with vapour barrier. I've only used water based paints with it though as it has long hoses and proper cleaning is a concern. I'm thinking I should probably invest in a low volume sprayer for cabinet work. The one I have is better suited for outdoor work or interior walls.

I finished the bookcases in Watco Danish Oil, but it's very labour intensive. Watco also penetrates well into the wood and acts as a stabilizer. Gives a nice satin finish after about 6 coats but the reflectivity varies over the surface where there are knots or rougher grain. Sanding sealer would probably help there, like your Timbermate filler. Takes a lot of coats applied with fine sandpaper to get a gloss finish. I haven't tried nitro-lacquer but should probably stick to something simple like shellac on my first project. I'll be sure to ask for advice in the forums when the time comes.

 

[MrBoat]

That's real nice too. Love the grain in that Birch. Thanks for the extra info. I have used epoxy plenty of times and I'm more than familiar with getting it on my fingers. Varsol removes it too but I should get some denatured alcohol. I usually use Orange hand cleaner with pumice afterwards to remove chemical residue from my hands.

Don't seem to have the variety of supplies in Canada but I have some woodworking friends that should have a line on where to get the proper epoxy. See mostly LePages and the containers are not that large. I have a high pressure sprayer but would have to set up a booth in the garage with vapour barrier. I've only used water based paints with it though as it has long hoses and proper cleaning is a concern. I'm thinking I should probably invest in a low volume sprayer for cabinet work. The one I have is better suited for outdoor work or interior walls.

I finished the bookcases in Watco Danish Oil, but it's very labour intensive. Watco also penetrates well into the wood and acts as a stabilizer. Gives a nice satin finish after about 6 coats but the reflectivity varies over the surface where there are knots or rougher grain. Sanding sealer would probably help there, like your Timbermate filler. Takes a lot of coats applied with fine sandpaper to get a gloss finish. I haven't tried nitro-lacquer but should probably stick to something simple like shellac on my first project. I'll be sure to ask for advice in the forums when the time comes.

White vinegar also gets uncured epoxy off hands and tools

Look for boat building supplies for epoxy, perhaps. Strip built canoes and kayaks use gobs of the stuff. That's where I got mine from, indirectly.

I have used Watco before. I wet sand with it before poly as a grain filler. I have natural, and walnut here.

Even the cheap (Harbor Freight?) HVLP sprayers work well. I got a cheapie off Amzon. I am pleased with it. The best part of that whole equation is my compressor. I have driers and such in the lines and a good pressure regulator. The other thing that makes gun spraying pleasant, is having enough thinner and rags on hand.

You can repair a flaw in lacquer nearly instantly with an eyedropper and sandpaper. It chemically bonds itself into previous layers without sanding. Really worth getting into if you are into finishing work. On something small like speakers, it's almost a joke because it's easy to get the surfaces perfectly wetted, without concern for overlap and overspray. There is also pre-catalyzed (precat) lacquer that professional paint stores carry that is quite nice too, especially when going for satin and matte finishes. Drawback being it has a limited shelf life due to the curing agent added.

For speakers this size, rattle can clear lacquer would work. I usually do 10-12 to allow for sanding/buffing. Lacquer, dries so fast, that you can do it anywhere you would use a rattle can outdoors. I get the best finishes outside. Wet the area down the night before and it's good all the next day. Whenever I try and do oil based indoors, I get dust in it.

 

[MrBoat]

Honestly, you could finish these well with spray cans. Lay on some good wet coats, and let cure for a month or so and just wait for a good day to sand, and put the final wet coat on. A good mild humidity day that is not too hot. They'll still look good up until then, and the orange peel will shrink back quite a bit and give you an idea what to expect. Or could steel wool them into a burnished satin finish, perhaps. I used part of a can of minwax lacquer here. There are probably better spray cans from those specializing in music instrument coatings, such as Mohawk. There are also some rather advanced spray can systems in the auto paint industry, including two part clear coats that are activated within the can at the time of application.

If you were to carefully grain your final sanding with say, 400 grit, you could give a more natural (albeit subtle) hand finished look. Weather is crappy here this weekend so I just put this on to cover the sanded epoxy and a head start, plus give me something to look at in the mean time.

 

[MrBoat]

Okay, so I went off on a bit of a side road, thinking that I build yet another pair of speakers with black baffles. I had some drops of the veneer left, and a .75" roundover bit. I had been mulling over hardwood edges and veneer center, hardwood edges with a painted center etc.

I could not tell if I want an all veneer speaker without building it and holding it up there. Okay, so I still don't know unless I put some finish on it. . . .then with the drivers installed. . . .

What say you folks? Too much mahogany?

 

[Alex2507]

Too much mahogany?

Hard to say ... without the finish on it.

 

[MrBoat]

Still kind of torn but the black does look good, too.

The magnets/motors on these little 4" Tang Band drivers is hilarious.

 

[Eppie]

I'm a fan of wood finishes but the black does look good as well. Sorry, not much help. Maybe rough out the speaker holes so you can see the veneered face with drivers in place.

How will the baffle be attached in final assembly? You used rabbeted joints for the cabs but looks like a butt joint remains. Some additional fasteners like biscuits?

 

[MrBoat]

I'm a fan of wood finishes but the black does look good as well. Sorry, not much help. Maybe rough out the speaker holes so you can see the veneered face with drivers in place.

How will the baffle be attached in final assembly? You used rabbeted joints for the cabs but looks like a butt joint remains. Some additional fasteners like biscuits?

Wood glue and clamps is all that is needed for the baffle. It's many times stronger than the MDF itself. The rear panels sit in rabbets and will just glue them in as well.

Since I had to set up the router and was destined for some outdoor time, I went ahead and did all the work on both baffles, since I have to set the router up for all the stages of each hole.

I do like the veneer fronts. Am going to use them since all the rest of my speakers are black faced. Thought of perhaps putting some guitar binding inlay between the two mating surfaces, but that's perhaps too much, too.

I needed a plunge-able surface to rout the holes so I just rolled up masking tape and used the cabinets, instead of dragging out clamps and such.

 

[Eppie]

Looks good. The drivers are relatively large compared to the baffle so I don't think that it's too much mahogany at all.

 

[MrBoat]

I collected some end grain (flour like consistency) mahogany sawdust and mixed it with epoxy to glue the baffles on. Both sides of the joint were primed with plain resin first, before the filler was added to makea thickened adhesive/filler.

This joint will get sanded flush and it will leave a pretty tidy glue line that should almost disappear under the clear coats. With epoxy, you want to leave some glue in the joint since it's film thickness is it's strength. The sawdust helps it from too much squeeze-out when clamped.

 

[Eppie]

Thanks Boat, it's those little details that have me guessing so these tips are really handy.

 

[MrBoat]

At least now I can use them until more favorable weather for spraying outdoors happens. I'll give them the spray can treatment which will still be ultimately compatible, without having to set up and then clean the paint gun for 1 coat. As much humidity as we've had lately, I'd have to add 10-15% retarder to keep from moisture clouding the finish.

 

[MrBoat]

Getting there. Everything works as it should. Will be done tomorrow. Just have a seal coat of spray bomb lacquer on them until sometime this fall/winter when the humidity is favorable. It's pure soup outside now.

Made a few mistakes along the way. Mostly due to butter fingers and getting in my usual job paced hurry. Since I made the new baffles separately from the case, I failed to (I'm using a circular saw) match the baffles perfectly with the boxes. The sides were fine but the top on one was just a 64th off, which may as well be an inch, when it comes to veneers meeting flush. I should have thought of this before I veneered the tops of the baffles. I should have tacked the baffles onto the boxes and run the flush trimmer around it once. I caught it on the second one.

Then, I sanded through the veneer on the top, thinking it was glue residue, until this glue residue, started getting bigger! This caused me to have to set up the router table and remove just the thickness of veneer on the baffle top, and redo it. I nailed it but it was difficult to gauge not only the thickness of the veneer, but the glue thickness as well. I took a wild guess on the glue part and it ended up perfectly flush with the rest. Now I do have some touchups where I sanded through stain left from the grain filler, again, just trying to get them sealed so that this humidity doesn't make the veneer start growing again.

 

[MrBoat]

They're not bad. Just did get the rear panels attached and binding post/port holes done. Waiting for all that to dry so I can finish these up, and onto the next project, or finish a couple I already started.

 

[MrBoat]

These are a potent little pair of speakers and they sound excellent. Not SPL monsters but plenty in the near field with some righteous bass. Great full range performance all around. My first go with ribbon tweeters and these are quite pleasant. Have played jazz and classic rock so far and it handles each well so far.

I have them paired up with my diy Icepower 200ASC amp with the Starving Student tube pre/headphone amp, which is perfect, albeit overpowered, unless one considers the benefits of ample headroom, and can behave with the volume knob.

Maiden voyage.

Some minor rookie mistakes that I didn't notice until too late. At the last minute, when I was wiring them up and putting the binding posts on, I took a chance and gave them the once over with steel wool and did a fast/wet coat of lacquer and it leveled very nicely on all sides. Wet enough to run for sure, but I held each side horizontal until it kicked, which is PDQ with spray lacquer. Each side was just on the verge of being too wet, with trying to cancel overlaps and overspray. At that point, I tell myself out loud to "stop right there." They came out looking quite nice, for what amounts to a sanding sealer coat. As far as the errors, I'll try harder next time to check myself more often.

Overall very pleased with what amounts to two little gems to add to the rotation, and a project worth doing.

 

[Pogre]

Great job man. Wish I could hear them! The rounded edges on the baffle are a really nice touch. That helps with diffraction as well, right?

 

[MrBoat]

Great job man. Wish I could hear them! The rounded edges on the baffle are a really nice touch. That helps with diffraction as well, right?

I think it helps with many, but some get by without it, but these had to be a little wider than stock due to using thicker material than spec'd so I added it. They sound awesome.

 

[Alex2507]

That helps with diffraction as well, right?

It makes 'em sound like speakers costing 5X more.

 

[MrBoat]

I made some quickie isolation wedges from scraps of wood and some 1" acoustic egg crate foam, which work surprisingly well, even though the cabinets were relatively quiet to the touch to start with. The weight does not compress the foam entirely, leaving the speakers somewhat 'boingy' on their little perches.

 

[Eppie]

Nice job Boat! How are you liking the all veneer exterior? Glad you didn't do black baffles?