Thompson Belly Reducer

Thompson Belly Reducer

Thompson Belly Reducer

Item # 1380
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$129.00

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Thompson Belly Reducer

About This Item

A lifesaving tool set for older acoustic guitars! Helps correct soundboard bulge caused by string tension, without replacing the bridge plate.

Excessive soundboard "bellying," caused by string tension, can make an acoustic guitar difficult to play. It can even damage the top, bridge plate and bridge. Replacing the original bridge plate to correct the problem is a time–consuming job that can unfortunately reduce the value of a vintage instrument.

Respected luthier and restoration expert TJ Thompson developed a simple tool set, the Thompson Belly Reducer, that can fix soundboard bulging without permanent alterations to the top or bridge plate.

The Thompson Belly Reducer is a set of five precision-machined aluminum tools: convex flatteners for vintage–style belly and rectangular bridges, and concave flatteners for the three most common bridge plate shapes.

Aligning the cauls is now easier—magnets are embedded right into the tools. Magnetic cauls stay in place (hands free!) while installing and tightening the clamps.

They're designed for use with the bridge removed from the instrument, and are effective for bridge plates that have been installed with hide glue, aliphatic (yellow) glue, or PVA (white) glue. Simply match the appropriate flatteners to your guitar, heat them to 150 degrees F, dampen the wood on the bridge area and bridge plate, and clamp the flatteners into place for a day or so.

Instructions included.

TJ Thompson recommends using three Ibex bridge clamps.



CALIFORNIA PROPOSITION 65 WARNING
WARNING: Cancer and Reproductive Harm - www.P65Warnings.ca.gov.


Video

Trade Secrets!

Trade Secrets!

Fixing a potbelly with the Belly Reducer

Dan Erlewine's got a Martin with a potbelly: string tension has pulled the top into a hump on this 1928 0-18. To make things tougher, the guitar top's encased in a thick layer of epoxy finish! It's an interesting puzzle...

Instructions

Product Instructions

Thompson Belly Reducer Instructions

The Thompson Belly Reducer is a simple tool designed to get rid of the bellying without making permanent alterations to the original guitar top.

Customer Reviews

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4.0
  • 4.04 average rating from 26 reviews
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5.0

Very Handy Tool

By

Verified Buyer


Invaluable for bridge belly issues. I've used these for all kinds of projects where heat can be handy. Forget using the glue pot to heat them. Using the microwave, I heat water to boiling in a large coffee cup and toss them in for a fast 150 degree shot.

5.0

Works great

By

Verified Buyer


I recently bought a Martin 1969 d 28 the bridge popped off and caused a beer belly on the guitar so I put the clamp on left it on for 2 days and it worked great now I can glue the bridge back on. I just followed the instructional video on it that is posted on the you tube channel.

5.0

Awesome tool

By

Verified Buyer


Wish I had this years ago; it is a fantastic tool that works as advertised. Easy to use and very effective. First job was a 1938 Gibson HG-0 that had a badly bellied top. It is now good as new. I can’t believe how well this tool works. I used my glue pot to heat the aluminum bars and it worked perfectly.

5.0

WELL DESIGNED AND EFFECTIVE TOOLS

By

Verified Buyer


I needed to correct the top on a 1966 Martin D-28, a guitar with great potential but abused in its past. The bridge had been shaved in lieu of a neck set so with the bridge removed, it was ready to test these belly reducers on. The reviewer that complained that they didn't hold their heat must have heated them improperly because I had no problems. The magnets are more than strong enough to hold their position. I backed the inside plate with a wood backing caul to get the clamps above the braces. I warmed them on a cast iron trivet atop my wood stove using the surface thermometer sold here. I heated them to the recommended 150F and could hear the moisture sizzle slightly as I placed them on the dampened bridge plate and top. Two applications and all the excess bellying is gone. T.J. Thompson knows what he's doing and these are great tools to have in the shop. I'll be using them with confidence and often.

1.0

belly reducer

By

Verified Buyer


1st impression is the magnets are not strong enough to hold the bridge plate piece in place. Nor do they hold heat. They were room temperature within 2 minutes.

Response from StewMac


Hi Peter,

Thank you for sharing your honest feedback with us. We're sorry the Thompson Belly Reducer didn't work for you as you expected. We stand behind our return policy -- if you are not satisfied with a product, you may return it anytime for a refund or exchange. Please call us at 1-800-848-2273. We look forward to helping you with this.

Response from StewMac


Hi Peter,

Thank you for sharing your honest feedback with us. We're sorry the Thompson Belly Reducer didn't work for you as you expected. We stand behind our return policy -- if you are not satisfied with a product, you may return it anytime for a refund or exchange. Please call us at 1-800-848-2273.

2.0

Good for it purpose.

By


I found the picture did not properly describe what you get when you purchase this.You have to read the fine print to know you don't get the C Clamp.The plates look fine.

5.0

Life Saver

By

Verified Buyer


Well worth the cost..the belly was so severe I applied two separate applications and man it returned it to a perfect scenario for getting a good set on the bridge re install

5.0

wow! amazing

By

Verified Buyer


belly be gone! 1 am a novice luthier, not a pro by no means,i used the Thompson belly reducer on my 1948 j 45 it had a bad bulge ,after unclamping after 38 hours, that belly was completely gone. I think the key is to soak the bridge pad and top area real well with hot water before clamping, my thanks to t.j Thompson, and stew mac

2.0

Just OK

By

Verified Buyer


I volunteered my ability to help restore instruments that were damaged in the Harvey storm.It was important that I keep the original bridge plate and although pretty high priced,I bought it.The magnets were not strong enough and I ended up having to hold the underside to get it in place.I was restoring a 1945 Martin 00 17 ,same thing Dan does the demo on.He didn't have trouble with his magnets.The belly flattened somewhat but this tool needs to go back to the drawing board.

4.0

magnets

By

Verified Buyer


I purchased this with the intention of using them when a job came in . Really keen to try the magnets.
left me flat , must be a really thick top and plate as they may as well not be there. A local luthier has made an electric heater for his set. put them in place and turn it on

Showing 10 of 26 Read more reviews >>
 


StewMac PDF Catalog, page 43 See Thompson Belly Reducer
on page 43 of our StewMac Digital Catalog