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I will be assembling my go-bar deck tonight. It will be 24" square and I will be using 24" long fiberglass bars. My question pertains to how far apart I should put the upper and lower deck. I have read that a 3-4" bend on the rods is sufficient.

So if I add the thickness of a radius dish and the thickness of the approximate height of what I am clamping (ie braces)to 20", I should be in the ballpark?

Thanks, Steve

There is two ways to do all the body clamping in the go-bar deck, or three maybe.

You can have different length go-bars for the different clamping, ie: bracing, top/back to rims.

You can make your deck so you can raise and lower the upper deck to adjust for different clamping lengths, ie: bracing, top/back to rims.

You can make large shim packs which your work sits on to adjust for different clamping lengths, ie: bracing, top/back to rims.

Hope this helps

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Three to four inches of bend is a lot. Depending how you are meassuring. I make my rods for bracing equal the deepest part of my dish and the bottom edge of the top of the deck less 1". This has worked well for me. I use 3/16" fiberglass round rods. I have two sets of rods for attaching tops and backs to rims also. I have 24 per top or back at 12 different lengths, each numbered as to the order they go. But all my rods for braces are basicly the same lenght. I am 24" inside height on my deck, 5/8 material thickness to the deepest part of my shallowest dish and 1" off of that gives me a rod length at 22 3/8" for bracing. I have 4 extras at 22" even for the heighest point of the x-braces on dreadnaughts but I dont use them much.

My bars are 24". The inside height of the deck is 28". I have a platform that is about 4" tall which is used for everything but gluing the top and back. The vertical supports are threaded rod, so I can vary the height of the deck, which I need to do since it's a bit short with the radius dish in the deck. Someone (Kathy Matsushita?) uses the "other half" of a pony clamp on pipe to allow height adjustments. Seems like they could be used on either the top or bottom, something I intend on looking into.

I think I tended to over-do it on bending/clamping pressure on a per rod basis, especially when clamping braces. I think the key here is using the low end of pressure per rod, with more rods to distribute the pressure evenly.

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I agree with Rod. My bars (also 3/16") are only about 1 1/2" longer than the distance from my work to the top of the deck. When I glue the top and back to the rim, I just made shorter bars, so there is no adjusting of the deck itself. Works well.

Ron

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I work Like Ron - One length for gluing braces, another for gluing tops and backs.

-Mark

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Thanks all for the quick replies. Given the supplies I have, I think I'll go with single length rods and a riser block when I get to that point.   

I also appreciate the need for less pressure but more evenly distributed. Trust me, after the questions on starved glue joints over the last few days, I will pay heed to the advice.

btw, I' will be using the 3/16 fiberglass rods with the cute little yellow plastic tips. I read in the archives where someone suggested using carpet on the top to reduce the possibility of the bars slipping. I may do that also.

Hesh, I didn't realize that you live all of 30 miles north of me. I was just up there before Christmas visiting a client. Small world...

Thanks again, Steve

Steve:

You might want to consider making a clamping caul for your tops and backs. I made one about 1 1/2 in. wide and about 1/4 larger than the guitar outline, out of 1/4 in. tempered hardboard. Didn't do this on the first back I glued, and found that the little plastic tips squeezed out a bit of oily residue. Not bad, but left noticible stains on the EIR. Fourtunately they seem to have sanded out! The caul will distribute the clamping pressure also.

-Mark

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[QUOTE=Mark Tripp] Steve:

You might want to consider making a clamping caul for your tops and backs. I made one about 1 1/2 in. wide and about 1/4 larger than the guitar outline, out of 1/4 in. tempered hardboard. Didn't do this on the first back I glued, and found that the little plastic tips squeezed out a bit of oily residue. Not bad, but left noticible stains on the EIR. Fourtunately they seem to have sanded out! The caul will distribute the clamping pressure also.

-Mark
[/QUOTE]

Hey Mark, do you mean basically making a doughnut of hardboard, 1-1/2" wide, shaped like the guitar such that the outer shape overhangs the guitar somewhat? I did a quick pic. Is this correct?



Thanks for the suggestion, Steve

Steve:

Exactly right!

-Mark

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That is what I did for awhile. Now I have little felt hammer on chair foot pads on the bottom of the rods I use to glue-up tops and backs. I find it easer to insure I have the rod directly over the glue joint. the hammer on cup on the chair pads fits my rods perfect.

Michael: Are you using the hammer-on pads that have a length of nail embedded in the center that is hammered onto the end of the rod (or chairleg)? If so, do you use wooden rods only? It would seem not so easy with fiberglass rods. Also, do you drill a pilot hole into the end of the rod? It's a neat idea, I'm just trying to be clear on how/what you hammer.

For fiberglass rods, do you (or others) think that CA gluing a round, 1/4" thickness of felt pad on the rod end would be a reasonable alternative?

Mark: That outline caul is a great idea! As you've done, it seems that the width of the donut would be best to keep thin so as not to distort the plate's arch near the edges.

What about using elastic wrap (bicycle tire, bungee cord, heavy rubber bands, surgical banding) for clamping the top and/or back to the rims? This seems like a great way to have the clamp follow the plate arch without distorting it.

Skip Skip Beach38728.4851851852

[QUOTE=MichaelP] That is what I did for awhile. Now I have little felt hammer on chair foot pads on the bottom of the rods I use to glue-up tops and backs. I find it easer to insure I have the rod directly over the glue joint. the hammer on cup on the chair pads fits my rods perfect.[/QUOTE]

Hammer-on chair foot pads? I confess I've never seen those. Are they something you find at the local hardware store? Would they work on 3/16" fiberglass rod?

Thanks, Steve

[QUOTE=sfbrown] [QUOTE=MichaelP] That is what I did for awhile. Now I have little felt hammer on chair foot pads on the bottom of the rods I use to glue-up tops and backs. I find it easer to insure I have the rod directly over the glue joint. the hammer on cup on the chair pads fits my rods perfect.[/QUOTE]

Hammer-on chair foot pads? I confess I've never seen those. Are they something you find at the local hardware store? Would they work on 3/16" fiberglass rod?

Thanks, Steve[/QUOTE]

I bet you have. They are round plastic foot pads with felt bottoms that have a metal sleeve that hammers into the foot of a chair. You can find them at Wal-mat, conv. stores and hardware stores. Actually the metal hammer in sleeve is 1/4 od and 7/32 id on most. I crimp them to fit 3/16 rods.

[QUOTE=Skip Beach] Michael: Are you using the hammer-on pads that have a length of nail embedded in the center that is hammered onto the end of the rod (or chairleg)? If so, do you use wooden rods only? It would seem not so easy with fiberglass rods. Also, do you drill a pilot hole into the end of the rod? It's a neat idea, I'm just trying to be clear on how/what you hammer.

For fiberglass rods, do you (or others) think that CA gluing a round, 1/4" thickness of felt pad on the rod end would be a reasonable alternative?

Mark: That outline caul is a great idea! As you've done, it seems that the width of the donut would be best to keep thin so as not to distort the plate's arch near the edges.

What about using elastic wrap (bicycle tire, bungee cord, heavy rubber bands, surgical banding) for clamping the top and/or back to the rims? This seems like a great way to have the clamp follow the plate arch without distorting it.

Skip [/QUOTE]

no not the nail type. These have a metal collar or sleeve about 1/8" tall 1/4" od x 7/32" id. That is the hammer in devise. I use the sleeve as a scocket for the rod.


Nothing wrong with gluing up bindings by wrapping, but I would think it would be hard to insure proper alignment attaching a top or bottom this way. Spool clamps are a great way to do this job but I like to leave my tops 1/4" over size( 1/8 to the side) till after glue up. For this reason I like to use my go-bar deck, radiused dishs and assembly molds. that way I cut down on required clamps and have a better visiual proof of the allignment.MichaelP38728.5162268519