bulging soundboard,loose bracing,

[geoff]

Hi all,

yep it's me again,

i have another guitar to practice on,

this is an Aria AW-100C.

it is a bit of a battle axe, looks like it has seen some better days, it has done some traveling as well.

I purchased this off Ebay for $66 ozzy dollars, the purpose of buying this was so i have a war horse to take away on the fishin trips, and not have to worry about it getting a new battle scar.

i knew it had the great looking screws in the bridge, so i had an idea the top might be bulging as well, and it is.

when i press on the bulge i can hear a distinct noise, the loose bracing in there, so that is another repair to be done.

 

I would really appreciate any input from you guys as to what to tackle first and how to go about the repais themselves.

 

cheers

geoff

[geoff]

and a couple more.

[geoff]

last one

[Eugen C]

I had a similar problem with my 12 strings Sigma-Martin, the top was bulged but the braces were not loose.
You have to glue the braces first, then repair the bulge and then glue the bridge.
You can search the forum for the topic "12 string Sigma with bellied top" to see how I solved the problem.

[geoff]

hi eugen,
i think i have read your thread, where you used a bridge doctor??

I would really like to know how i go about fixing the loose bracing, and whether i can leave the top on to do all the repairs?
i dont want to go further than i have to!!!

cheers
geoff

[Bob Steinarsson]

The bracing has probably become loose because of the bulging of the top. I don't think that you will be able to fit the stiff and probably quite straight bracing to the bulging top. This means that both the top and the bracing must get flat to fit each other. The plastic bag trick from Eugen's thread will do the job for you. It will flatten the top, and the bracing will get soft enough to fit it. Clamp the bracing with a wooden stick while the glue and the guitar dries up again. Then install the BD, and the top will never bulge again.

Check the progress of the flattening often, and take care that the wood doesn't get really wet.

Good luck!
BS

[Ned Knepp]

I think I would try to flatten the bulge mechanically. The humidity approach may well help too but I think clamping a board across the bulge would let you check on the extent of the brace situation with more accuracy and more quickly.

I have a couple of syringes that have long tubular extensions that are handy for squirting Titebound where I need it. I flattened the end of one of them a bit. I have to be careful that I don't exert too much pressure or the tube will come off and the glue will squirt everywhere. I also thin the glue just a bit (not much) with some water so it will flow better. I use a small thin pallet knife to spread glue into the tight areas where the tube can't be inserted. It's messy, working through the sound hole but I wouldn't remove the back or face unless you absolutely have to.

The real gotcha for me is usually bracing things until the glue dries. I made some "jacks" from turn buckles that I purchased at the hardware store with padded wooden dowel sections on the ends. "These work but it's sometimes a pain to hold them and turn them through the sound hole. Lately, I been using wedge sticks, that is some sticks that are just a bit too long to fit so they can be wedged into place. I cut a bit of a "V" in the ends so they are much less likely to slip off glued brace.

BTW, this is also a reason to use a plank of wood on the face to flatten it out. It acts as a surface to brace against.

Long hemostats are almost invaluable in cleaning up glue. They can help you insert the props in those areas that you can't reach by hand.

It is possible that you will not need a Bridge Doctor once you get the braces glued back into place. If you decide to install one, I recommend that you purchase one at least for the first time so you can see exactly what they are and how they work. Their primary purpose is to control bridge rotation, not cure the sort of bulging that results from loose braces.

Ned

[geoff]

hey all,
thanks for the replies so far,
Ned, i like the idea of the mini gobars, that makes great sense, and easy enough to make.
just on the humidity, i get that putting the wet towel in a plastic bag, but is any heat introduced to increase the humidity? do i put the bag directly on the affected area, or opposite it???

i dont have any titebond glue, and haven't been able to find any locally, would PVA glue do the trick???

i dont mind trying to make the bridge doctor, and yep i see what you are saying Ned about the anti-rotation effect of it.
only a matter of measuring up my guitar in some key places and it shouldn't be too hard to whip up a plan for one.

i just had to google what hemostats where.
they look long and handy.

cheers
geoff

[Ned Knepp]

Geoff,
If you put the wet rag in a plastic bag with a few holes in one side, you can lay the bag in your guitar (laying down in the case) and close up the case. Leave it flat and closed for a few days. The water in the rag will humidify the guitar.

I haven't used this technique in this manner and I'm not sure if it is really going to help you much. I use it for cracks that appear to be humidity related. I recently needed to do this to the parlor I'm rebuilding but I don't have a case for it. I used a balloon, inflated inside the soundhole to seal the body. ( I think the idea came from someone here but I can't remember who suggested it. ) It works like a charm.

I don't know what to tell you about the glue. I use titebond or hide glue, depending on the instrument and the application. I don't now where you are located so I can't even do a internet search for something comparable. Perhaps one of the other Posters will have an idea.

The Bridge Doctor is fairly simple but I think it is also elegant in it's simplicity. I'm very glad that Eugen's home made version worked so well for him but I can't help wondering if the extra mass would work as well on a 6 string. I would suggest that you use a single screw through the back of the bridge to keep down the mass.

Ned

[geoff]

Hi Ned,
yep single screw is already in the bridge, that is how the previous owner fixed a loose bridge problem 3 screws.
i am located in australia, east coast NSW
i see the australian luthier supplies sells it, but i was hoping to find some on the shelf somewhere.

i dont have a case for this guitar either ned so if i try the humidity thing i will give the balloon a go.

looking at the bridge doctor pictures on Stewart macdonlads website, it looks much thinner than eugen's.

cheers
geoff

[Eugen C]

I made the Bridge Doctor using the dimmensions they put on the webpage.

[geoff]

i didn't see any dimensions eugen

[Eugen C]

http://www.stewmac.com/shop/Tools/Special_tools_for_Bridges/JLD_Bri...

From Details:
"The spruce block is 3/4" x 1-5/8" x 3-3/8" tall. The 1/4"-diameter tension rod is 9" long. The mounting post has three different positions to accomodate a variety of bridge styles. #3694 includes a white pearl dot to hide the bridge screw.
"