BillFitzmaurice.info

Hi there!

First of all I want to thank each and everyone that posted on

http://billfitzmaurice.info/forum/viewt ... =1&t=21239

which is the thread that started all this.

Your help and advice is invaluable and thank you for spending the time to educate me on this matter.

For anyone that isn't familiar with this thread,

we're from Lisbon, Portugal, current plan is to build a couple of T48s.

We went with 12'' driver because as we have never heard a BFM design we're still open to building a T60 if we're not pleased with the design, hence having the driver we can use on both.

That being said, we've finally found some decent ply and had it professionally cut from a carpentry.

Also we chose a "weird" width, as it's 19,78 inch which for us means 50 cm which is perfect.

already marked the panels, and finished the baffle / anchor. and got panel 1 glued.

Left reducers glueing yesterday, plan to get panel 2 installed tonight.

We all work full time jobs so it's hard to get time to work on this, but we plan on doing one panel per day at the end of each work day.

I don't have a lot of photos with me, will try to upload when I get home, but anyway here's one of me attaching the screw blocks to the anchor.

Updates soon. And most likely a lot of questions. Cheers.

and one with the fully assembled baffle with speaker installed

Congratualtions on starting, and on finding good wood.

One panel per day is good progress. It allows you to think about the next step, without rushing, and this will lead to an excellent product.

By the way, are you using an expanding polyurathane adhesive?

Tom Smit wrote:Congratualtions on starting, and on finding good wood.

One panel per day is good progress. It allows you to think about the next step, without rushing, and this will lead to an excellent product.

By the way, are you using an expanding polyurathane adhesive?

hey, yes I can take a picture of the exact one we are using, but I was assured by a retailer that it was similar to pl premium. that product isn't carried here in Portugal, and at least on the label it states mostly the same information.

waterproof, 200kg strength, polyurethane adhesive, paintable, and it states lastly that it's "made for surfaces that are under extreme vibrations".

I've found it online,

http://www.aki.pt/produto.aspx?category ... bsIdeias-1

the website is in Portuguese but I think the brand is international so you may be familiar with it.

Here's a few photo updates, glued panel 3 yesterday. plus bonus baffle / panel 1 join, and underside of reducers.

OK, we have a problem,

it seems that our baffle has about 2 mm difference in size, I guess the blade must've slipped a bit on our carpenter....

So panel 4 doesnt fit properly.

Our possibilities would be to try to cut just a bit of ply and glue inbetween ( having panel 4 slightly off panel 3) or to try and re-cut panel 4 with those 2 mm offset.

What to you think would be the best option ??

Pic attached so you'll see what I mean

Adhesive should fill that gap.

Bill Fitzmaurice wrote:Adhesive should fill that gap.

Just apply on both panel 2 and 4? and when i get them close together the adhesive should bind right ?

is it worth cutting a 2mm strip of wood just to try and stick it down the gap ? just so the gap would be less than 1mm

?

Cheers

The adhesive should be good enough to fill the gap. I most likely would put adhesive on the bottom of the panel and install it (all joints dampened). After that, just fill in the gap with the caulk gun.

If it really bothers you, you could put a sliver of wood in there, but it's not necessary.

jmanso wrote:

Bill Fitzmaurice wrote:Adhesive should fill that gap.

Just apply on both panel 2 and 4?

Lock the panels in place with jigs, fill the gap with adhesive. Make sure it's completely cured before removing jigs.

Also,
Check that the side which you are attaching the panels to is flat.
If the side has warped/bowed, it may also explain the gap.

To check, clamp or screw a big solid de warping board to the side panel, and see if the gap has closed at all.

Hi there, I don't have any pics with me at the moment,

but when we clamped panel 4 to side panel the top gap was almost 9 mm !! we've decided to recut panel 4 entirely with that side discrepancy making it larger on one side instead of perfect rectangle.

it now sits perfectly and is perfectly leveled on all three edges (baffle, panel 3 and side panel)

we'll glue it tonight, pics soon.

also, we're just using glue and jigs instead of screws because of our inexperience with woodworking.

just a simple question. if we wanted to secure panels in place with screws, I assume I'll have to predrill the side panel but do I also pre drill the side of the panel to be secured, or just hold it in and drill the screw in ??

Cheers

edit:

also we are still thinking about what finish to apply because duratex is really hard to come by in here. I've not seen anyone using some wood varnish finish in these type of cabs: is it because it just cracks or just because not worth it since speaker is not meant to be upright ?

I experienced the exact same issue last night with the gap between panel 2 and 4. I just loaded it up with PL and gave it a thick bead on either side of the join to be absolutely air tight.

You both need to ensure the side panel is still flat.
Put a long straight edge rule on the panel as it sits to determine flatness.
Add dewarping boards if required.
You also may need to assess if panel 1 is in fact square to the side.

If you just recut panels but don't address a warped side panel, you will have more issues later with the other side and the cab being out of square/warped...