What's to chat about?

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Strange Kevin
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Re: What's to chat about?

#496 Post by Strange Kevin » Mon Mar 30, 2020 6:40 am

If it's really bad you could sand it down a little. But I rarely do when I end up with any imperfections.

I'll usually get a line out of Duratex on the handle side of the roller if I'm pushing down too hard. Just keep it light on your final passes like Bruce mentioned.
Authorized Builder - Phoenix AZ.
Main Rig - 6 DR200s - 6 T48s (30")
SLA Pros for the smaller stuff.

Bruce Weldy
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Re: What's to chat about?

#497 Post by Bruce Weldy » Mon Mar 30, 2020 9:40 am

SethRocksYou wrote:
Mon Mar 30, 2020 12:26 am
Bruce Weldy wrote:
Sun Mar 29, 2020 10:36 pm
It's just a matter of touch.....once the duratex is spread, keep going over it both directions and at an angle, then finish with very, very light passes in a straight line overlapping...
So, do you think I should sand the existing texture down first or just go right over the top of what's already there?
Go right over the top.....it's just a shading issue...another coat will fix it up.

6 - T39 4-25" 2-22" 3012LF
4 - OT12 2512 Melded/NSD2005
1 - T24
2 - XF210


"A system with a few knobs set up by someone who knows what they are doing is always better than one with a lot of knobs set up by someone who doesn't."

himhimself
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Location: Bloomington IN

Re: What's to chat about?

#498 Post by himhimself » Mon Mar 30, 2020 2:02 pm

However, if you ever do try Baltic Birch....you'll never go back...just warning ya'....
[/quote]
At the moment, I do not regret the route I've chosen. It's not that big of a deal. Would just like to investigate other filler options.

I'll be doing the shorty SLAP's in BB. The Alpha 6's arrived today. As of a couple days ago, the lumber yard is still open. Probably pick a sheet up Tues or Wed. I'll put those together before I get the 4 30" T39's started.

The choice of material was driven by weight not dollars. So, it would be buy once, cry every time I lift them.
[/quote]

With regard to weight, I've wondered about taking two sheets of 1/4' ply, swiss cheesing one paying attention to where joints would lie, and then laminating them together with wood glue in a press. I would think you could reduce the weight of those panels by 25-30% if weight reduction was the top concern. I know my 1/4' thick otop jarrays with plenty of bracing are super strong.
2xT30 (20", 3012lf)
4xOtop Jarray

SethRocksYou
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Re: What's to chat about?

#499 Post by SethRocksYou » Mon Mar 30, 2020 4:26 pm

himhimself wrote:
Mon Mar 30, 2020 2:02 pm
With regard to weight, I've wondered about taking two sheets of 1/4' ply, swiss cheesing one paying attention to where joints would lie, and then laminating them together with wood glue in a press. I would think you could reduce the weight of those panels by 25-30% if weight reduction was the top concern. I know my 1/4' thick otop jarrays with plenty of bracing are super strong.
I think if I wanted to try to build an ultralight Titan/Tuba I'd cut 2-3" x 48" strips of 3/8" XPS and sandwich them between 3/8" x 48" of 1/4" ply creating a sheet and fiberglass both sides up to a nominal 1/2" thickness. Assemble the cabs with the plywood strips across the width and use extra 1/4" bracing at closer intervals than usual, 3.5" - 4"ish apart. Or what ever seems appropriate.

It would be a fun project. But, for the time being, I'm content with just choosing a lighter species of ply for this particular project. The pine ply I got is right about 40lb/sheet. Adding 10% to account for inconsistencies and comparing it to the reported weight of ½" BB, 55lb/4x8 sheet (43lb/5x5 sheet). Calculating that all out equates to a minimum lumber weight for a 30" wide T39 of 87lb if done in BB, 70lb if done in Douglas Fir. 17lb is way worth it in my book.
Last edited by SethRocksYou on Tue Mar 31, 2020 1:58 am, edited 1 time in total.

Bruce Weldy
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Re: What's to chat about?

#500 Post by Bruce Weldy » Mon Mar 30, 2020 5:44 pm

My thinking is kinda' opposite.....the Titans have wheels and are easy to manipulate by yourself even at 85 pounds. So don't worry about heavy, just get the nice straight panels and cut down on build time and effort.

It's the tops where I'd rather go light....those dogs have to be lifted in the air every time!

6 - T39 4-25" 2-22" 3012LF
4 - OT12 2512 Melded/NSD2005
1 - T24
2 - XF210


"A system with a few knobs set up by someone who knows what they are doing is always better than one with a lot of knobs set up by someone who doesn't."

Grant Bunter
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Re: What's to chat about?

#501 Post by Grant Bunter » Mon Mar 30, 2020 5:57 pm

Bruce Weldy wrote:
Mon Mar 30, 2020 5:44 pm
My thinking is kinda' opposite.....the Titans have wheels and are easy to manipulate by yourself even at 85 pounds. So don't worry about heavy, just get the nice straight panels and cut down on build time and effort.

It's the tops where I'd rather go light....those dogs have to be lifted in the air every time!

Except when the cabs will have to be carted to barges or boats, via other boats, and will also involve trucks and docks and stuff.
Since that's in two directions, with a gig in-between, I get you'd want to shave off every ounce you could if that was the case for every gig you did...
Built:
DR 250: x 2 melded array, 2x CD horn, March 2012 plans.
T39's: 4 x 20" BP102 , 2 x 28" 3012lf.
WH8: x 3 with melded array.
Bunter's Audio and Lighting "like"s would be most appreciated...

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Re: What's to chat about?

#502 Post by SethRocksYou » Mon Mar 30, 2020 6:17 pm

Bruce Weldy wrote:
Mon Mar 30, 2020 5:44 pm
My thinking is kinda' opposite.....the Titans have wheels and are easy to manipulate by yourself even at 85 pounds. So don't worry about heavy, just get the nice straight panels and cut down on build time and effort.

It's the tops where I'd rather go light....those dogs have to be lifted in the air every time!
I'm thinking, your thinking would be, what my thinking is, if you had to lift them, I think. :mrgreen:

Yeah, if I didn't have to lift them, I would have just done them in BB. But, I do. :(

Here's an interesting tid-bit, a full width 12" loaded T48 is only 5-6lb heavier than a full width 12" loaded T39. Where a 20" wide single 12 loaded T60 is 93lb in Doug Fir, 116 in BB. I found that interesting.
Last edited by SethRocksYou on Tue Mar 31, 2020 4:54 am, edited 1 time in total.

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Re: What's to chat about?

#503 Post by SethRocksYou » Mon Mar 30, 2020 6:18 pm

Grant Bunter wrote:
Mon Mar 30, 2020 5:57 pm
Bruce Weldy wrote:
Mon Mar 30, 2020 5:44 pm
My thinking is kinda' opposite.....the Titans have wheels and are easy to manipulate by yourself even at 85 pounds. So don't worry about heavy, just get the nice straight panels and cut down on build time and effort.

It's the tops where I'd rather go light....those dogs have to be lifted in the air every time!

Except when the cabs will have to be carted to barges or boats, via other boats, and will also involve trucks and docks and stuff.
Since that's in two directions, with a gig in-between, I get you'd want to shave off every ounce you could if that was the case for every gig you did...
Exactly. :thumbsup:

Bruce Weldy
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Re: What's to chat about?

#504 Post by Bruce Weldy » Mon Mar 30, 2020 6:32 pm

SethRocksYou wrote:
Mon Mar 30, 2020 6:18 pm
Grant Bunter wrote:
Mon Mar 30, 2020 5:57 pm
you'd want to shave off every ounce you could if that was the case for every gig you did...
Exactly. :thumbsup:
I don't do those kind of gigs.... :mrgreen:

6 - T39 4-25" 2-22" 3012LF
4 - OT12 2512 Melded/NSD2005
1 - T24
2 - XF210


"A system with a few knobs set up by someone who knows what they are doing is always better than one with a lot of knobs set up by someone who doesn't."

Grant Bunter
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Re: What's to chat about?

#505 Post by Grant Bunter » Mon Mar 30, 2020 6:35 pm

Bruce Weldy wrote:
Mon Mar 30, 2020 6:32 pm
SethRocksYou wrote:
Mon Mar 30, 2020 6:18 pm
Grant Bunter wrote:
Mon Mar 30, 2020 5:57 pm
you'd want to shave off every ounce you could if that was the case for every gig you did...
Exactly. :thumbsup:
I don't do those kind of gigs.... :mrgreen:
Me either...
Built:
DR 250: x 2 melded array, 2x CD horn, March 2012 plans.
T39's: 4 x 20" BP102 , 2 x 28" 3012lf.
WH8: x 3 with melded array.
Bunter's Audio and Lighting "like"s would be most appreciated...

Grant Bunter
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Re: What's to chat about?

#506 Post by Grant Bunter » Mon Mar 30, 2020 6:43 pm

Have I missed this somewhere along the way?
You're doing 1/4" braces in the T39's?

Cheeseholed 1/4" will be way less weight than cheeseholed 1/2".
Dadoed, so there's no screws or nails.

I normally remember such things, but somewhere here in the forum, in my time, is an ultra light T39 made wholly out of 1/4", and the weight saving was significant, even though bracing was upped so much one might think it couldn't possible be lighter, but it was.
Now who did that baby...
Built:
DR 250: x 2 melded array, 2x CD horn, March 2012 plans.
T39's: 4 x 20" BP102 , 2 x 28" 3012lf.
WH8: x 3 with melded array.
Bunter's Audio and Lighting "like"s would be most appreciated...

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Charles Jenkinson
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Re: What's to chat about?

#507 Post by Charles Jenkinson » Tue Mar 31, 2020 1:36 am

Was it a 1/4, or 3/8....?

Harley rings a bell, Grant.
2xJ12L (3012HO) switchable/melded
2xT30

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SethRocksYou
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Re: What's to chat about?

#508 Post by SethRocksYou » Tue Mar 31, 2020 2:49 am

Grant Bunter wrote:
Mon Mar 30, 2020 6:43 pm
Have I missed this somewhere along the way?
You're doing 1/4" braces in the T39's?
I've considered it. But, no. I don't plan on going that far with the lightening on this build. Could happen though. I'll see if the price of 1/4 BB is enticing enough when I grab a sheet of ½" BB for the shorty SLAP's. So, could happen I suppose. Hadn't planned on it though.

I only mentioned it in the context of an ultralight sandwiched foam core composite/fiberglass/carbon fiber sort of build.

Grant Bunter
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Re: What's to chat about?

#509 Post by Grant Bunter » Tue Mar 31, 2020 3:45 am

Charles Jenkinson wrote:
Tue Mar 31, 2020 1:36 am
Was it a 1/4, or 3/8....?

Harley rings a bell, Grant.
You're all over it Charles!

viewtopic.php?f=30&t=18362&hilit=Light+T39

Unfortunately the pics are gone...
Built:
DR 250: x 2 melded array, 2x CD horn, March 2012 plans.
T39's: 4 x 20" BP102 , 2 x 28" 3012lf.
WH8: x 3 with melded array.
Bunter's Audio and Lighting "like"s would be most appreciated...

SethRocksYou
Posts: 903
Joined: Thu Sep 10, 2009 8:06 pm
Location: Sacramento, California, USA
Contact:

Re: What's to chat about?

#510 Post by SethRocksYou » Tue Mar 31, 2020 4:49 am

Grant Bunter wrote:
Tue Mar 31, 2020 3:45 am
Charles Jenkinson wrote:
Tue Mar 31, 2020 1:36 am
Was it a 1/4, or 3/8....?

Harley rings a bell, Grant.
You're all over it Charles!

viewtopic.php?f=30&t=18362&hilit=Light+T39

Unfortunately the pics are gone...
:shock: Had I known the option was an option... I'd have done this first one in 1/4" or 3/8" before pulling the trigger on the rest. I'd have happily put in the extra work on the build to have it be adequately braced. Thanks for the link Grant. :thumbsup:

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