Started the T39's with a cabinet maker

[Dan56]

Hello,

Before I get a lot of flack for not following the plans and not using butt joints, if this were just me doing the builds, then yes I would be following the plans exactly. However, I am very fortunate to have a highly skilled and equipped cabinet maker for the bass player in our band so...

I thought this would be interesting to those who are curious about a build using rabbets and dados. The layout and cutting has been done by Tim (my bass). I'm holding the plywood. Well I did do the organizing, sourcing of parts (not the wood) and build sheet of cuts and build order. Besides, I made the most important decision: to build BFM's cabs. Oh yeah, it's my money.

I'm perfectly capable of having built these cabs via the plans (I bought my delta contractor saw in 1988) but there is something about working along side a master. They make it look so easy. Kind of like watching Bob build his master system for here in Providence.

The rabbets and dado's have allowed the construction to proceed without the need for a lot of support of the panels. Tim also mitered the joints and this made squaring up the parts almost automatic. Getting the angles and transferring them to the saw seemed effortless.

The panels have not been glued to the side panel. It is funny, in that Tim mentioned putting in Panel 9 would be very difficult with them in the way. I noted I had read that some found that the hardest part. So, we will glue up the top, side and back then put in place Panel 9. After that, the panels for the porting you see here will be glued in.

[BrentEvans]

Before I get a lot of flack for not following the plans and not using butt joints, if this were just me doing the builds, then yes I would be following the plans exactly. However, I am very fortunate to have a highly skilled and equipped cabinet maker for the bass player in our band so...

As long as your build comes out structurally identically, the method of fastening isn't as important. Staples, glue, clamps, screws, whatever works. As long as everything is in the right places and glued properly with the correct adhesive, it's fine. The only thing we find with pro cabinet builders that aren't intimately familiar with BF designs is that sometimes things are skipped that really need to be in place or corners cut that shouldn't be (sometimes quite literally).

The rabbets and dado's have allowed the construction to proceed without the need for a lot of support of the panels.

You're referring to temporary supports, and are still planning to put the horn path braces in, right? My plans are older, but it does seem that some of the braces should already be in place. The braces keep the panels from rattling under pressure, not just to make the installation go more smoothly.

If you haven't glued the sides on, it's not too late to put them in. It will be a little hard to fasten them inside the chamber, but it should still be doable.

[Dan56]

As long as your build comes out structurally identically, the method of fastening isn't as important. Staples, glue, clamps, screws, whatever works. As long as everything is in the right places and glued properly with the correct adhesive, it's fine. The only thing we find with pro cabinet builders that aren't intimately familiar with BF designs is that sometimes things are skipped that really need to be in place or corners cut that shouldn't be (sometimes quite literally).

You're referring to temporary supports, and are still planning to put the horn path braces in, right? My plans are older, but it does seem that some of the braces should already be in place. The braces keep the panels from rattling under pressure, not just to make the installation go more smoothly.

If you haven't glued the sides on, it's not too late to put them in. It will be a little hard to fasten them inside the chamber, but it should still be doable.

Yes, interestingly enough I did have to explain to Tim that the cover was the sealed access panel and not just a cover to protect the speakers when moving them. He was looking at the sketchup and not the plans. Had to convince him about polyurethane glues. Today he noted it is better with end grain gluing. So he's doing his homework. With that, nothing as to parts and structure are being changed. Just a bit of joinery difference is all that I thought the members would find interesting.

No the sides are not permanently attached. What you see here is simply the combining of the panels that make up the tube using the one side to register their positions. As it sits currently, waiting for the glue to have dried, the baffle with panel 3 and 4 can lift out as one solid unit. Same goes for panel 5 and 6. It's kind of a "modular" build you could say.

Yes, I was referring to the supports used to stabilize panels as they are joined and the glue sets. The braces will all go in the same as if the structure were built butt jointed. The top, side and back will be assembled. Panel 9 put in place and then the 2 assembled units will be permanently attached to the side and panel brace inserted.

I suggested we cut all the braces per the plans as to their angles. Well this is where the cabinet maker comes in. We will be determining the specific angle for each set (panels 3/5, panels 5/8 and panels 4/6) so that the joints are as gapless as possible and the spacing between panels is parallel. He wants to do it. Over kill? Sure. Craftsmanship? For sure. The only other person in my life to work like this is my brother and he learned from a shipwright. Talk about fitting wood.

[Bill Fitzmaurice]

Some of the best build results have been obtained by guys with little to no experience building cabs, while some of the worst have come from guys who were highly experienced, and due to being highly experienced assumed that they knew more about how to build these cabs than the person who invented them.

He was looking at the sketchup and not the plans.

[Tom Smit]

I'm glad that you talked him into using PL as I see plenty of squeeze-out on the panels. I was worried about the side panel to be honest. I hope that the panels don't warp slightly when pulled out of the side. I might might be concerned needlessly, I don't know, but I hope the assembly drops right back in to the dados.
Looks good so far.

[Bill Fitzmaurice]

I'm glad that you talked him into using PL as I see plenty of squeeze-out on the panels.

So do I, but judging by the color I suspect that it's not PL Premium construction adhesive, but rather Gorilla Glue or something similar.

I hope the assembly drops right back in to the dados.

That, along with their not being worth the added complexity that they add to the build, is why I don't use them. If the panels are the slightest bit off from absolutely perfect you won't be able to get the second side on.

[Dan56]

I'm glad that you talked him into using PL as I see plenty of squeeze-out on the panels.

So do I, but judging by the color I suspect that it's not PL Premium construction adhesive, but rather Gorilla Glue or something similar.

I hope the assembly drops right back in to the dados.

That, along with their not being worth the added complexity that they add to the build, is why I don't use them. If the panels are the slightest bit off from absolutely perfect you won't be able to get the second side on.

Yes, I'm waiting to for my order with the PL to come in before we go further.
Yes, the dados add complexity and I would not have chosen to do such. But, as I noted he does not mind the work. Because he is now the VP at the high school and does not get to do such work as much, this project is an escape and opportunity to use his talents.

Dan

[subharmonic]

Your a little far to be waiting for the right glue. You nay consider scapping this build and starting over, reserving whatevere wood you can for the rebuild. It can't stated enough how bad airleaks no matter how small are for performance of these cabs.

Use a bright light on the opposite side of your joints in a dark room.ANY light sneaking past needs to be dealt with as an airleak. Trust me, the airtight cab is different monster than one with even a pinhole.

[MissileCrisis]

I've done dado's for braces, quite useful. Routing the entire side panel? good luck .

[Dan56]

Your a little far to be waiting for the right glue. You nay consider scapping this build and starting over, reserving whatevere wood you can for the rebuild. It can't stated enough how bad airleaks no matter how small are for performance of these cabs.

Use a bright light on the opposite side of your joints in a dark room.ANY light sneaking past needs to be dealt with as an airleak. Trust me, the airtight cab is different monster than one with even a pinhole.

I do appreciate everyone's concern, truly. As to the glue, I have done much research on poly glues (it's in my nature and my training, I spent 2 weeks steady just researching mattresses before I laid down the money). I have used Gorilla in particular for splice joints on mahogany making bows to cover the metal tubing bows of my commercial greenhouse. No failure in 7 years. Though the tubing collapsed 2 years ago do to heavy wet snow.

However, I do solemnly promise to post a new thread where if what Tim has done flops (and it will be his money buying the new wood) you can all have a round of "I told you so" with all the modicons you desire. I will take it with honor. I promise.

[Dan56]

I've done dado's for braces, quite useful. Routing the entire side panel? good luck .

Well, it's not my problem. It is Tim's and he has no doubts. Plus, we've already dry fit it all. The man is exact in his work. But, as noted with my other post, I will accept all the "I told you so's" if it comes to that and Tim will be buying new wood.

[subharmonic]

I have used Gorilla in particular for splice joints on mahogany making bows to cover the metal tubing bows of my commercial greenhouse. No failure in 7 years.

It is not a concern about joint failure structurally, it is about airleaks. That stuff is runny so it could help or hinder.

If you are moving forward try the light trick. It saved my ass many times.

However, I do solemnly promise to post a new thread where if what Tim has done flops (and it will be his money buying the new wood) you can all have a round of "I told you so" with all the modicons you desire. I will take it with honor. I promise.

We aren't looking for a . It is all about the fact that some of us have tried to cut corners and/or had a "old pro" help and it turns out to cost more money and time. I tried truck bed liner instead of duratex, it cost me so much time (had to move the build per the wife to a detached shed and heat it in ND in the winter). To save $10 it cost me that in electricity. Also so first timers can heed the warnings.

[Dan56]

If you are moving forward try the light trick. It saved my ass many times.

We aren't looking for a . It is all about the fact that some of us have tried to cut corners and/or had a "old pro" help and it turns out to cost more money and time. I tried truck bed liner instead of duratex, it cost me so much time (had to move the build per the wife to a detached shed and heat it in ND in the winter). To save $10 it cost me that in electricity. Also so first timers can heed the warnings.

Air leaks I get. I can use light on the mitered panels, but I'll be using air on those set in the rabbets and dados.

We are not cutting corners, I want to stress that to anyone else who is thinking of building any of these designs. We are not leaving out parts or changing the design in anyway. Fortunately I had read about the difference in product regarding duratex and the poly bedliners and other poly type sealers used in the auto industry. It's just the glue and that is only because Tim went ahead with the Gorilla.

[BrentEvans]

Dan, the Gorilla product isn't recommended in the plans because it's not foolproof. It CAN work, but only if the joint is perfect. It seems you do have a competent builder, but why take the chance? On the joints that are already made, go over the joints with a healthy coating of silicone. On the joints that remain, do yourself a favor and have him use the PL premium. The thicker consistency of the PL product prevents leaks. The Gorilla product holds great, but the expansion tends to have large bubbles, and air can get through in places that you can't see with a light and that aren't really testable until you fire up the cab. Your build might be ok, but you might not. Why risk it?

By the way... we don't want to tell you that we told you so. We want you to have a great cab, and there is a vast expanse of experience in this community that is trying to warn you of a big problem that can arise. We just want you to be happy!

[Dan56]

Dan, the Gorilla product isn't recommended in the plans because it's not foolproof. It CAN work, but only if the joint is perfect. It seems you do have a competent builder, but why take the chance? On the joints that are already made, go over the joints with a healthy coating of silicone. On the joints that remain, do yourself a favor and have him use the PL premium. The thicker consistency of the PL product prevents leaks. The Gorilla product holds great, but the expansion tends to have large bubbles, and air can get through in places that you can't see with a light and that aren't really testable until you fire up the cab. Your build might be ok, but you might not. Why risk it?

By the way... we don't want to tell you that we told you so. We want you to have a great cab, and there is a vast expanse of experience in this community that is trying to warn you of a big problem that can arise. We just want you to be happy!

Ok, I guess my sense of humor does not come through well. It's that internet thing. But honestly, I truly appreciate everyone's concern and I am heeding it all. I'm not a gambler, and I don't risk doing things twice.

Yes, light will not test a dado or rabbet joint. But, how about blowing 125lbs of air along the joint if I need to and see what happens to baby power or talcum powder spread along the opposite side. Or better, powdered colored poster paint. Or line chalk. We'll have some psychedelic effects inside the cab when it's done. Tie dye like.