Tube Amp Archive

Hi everybody,
I have a 1969 Fender Twin Reverb, and the other day, it's original particle board speaker baffle decided to separate itself from the rest of the amp. It just fell out...

So, I was wondering if anyone might have some inventive ideas about the best way to repair and/or tighten up the screw holes, so the screws will again hold the baffle in place.

Thanks in advance,
LDC

I've always repaired stripped out screw holes by coating a matchstick with Elmer's glue and forcing it into the hole. When it dries you can take a chisel and trim it down flush. Ta Daaaa! New wood.

LeeMo

Matchsticks and glue are a very old carpenter's trick. Older than everyone here. It's a time tested method. If you want something with more density than matchsticks, you can drill it for 1/8" dowel (if you can find it) or 3/16" dowel. Like the match stick method, it is a plug and glue method. If you use dowels, work carefully. The fit tends to be tight, giving you one chance to put the plug in right (no test fitting.) Both variations of this method should work fine.

You might consider going to the auto parts store. Look in the body work section. They sell a binary putty -- black and grey. The small package should be around $5. You break off a small bit and knead it to mix the two compounds. Then press it into the hole. It sticks to nearly everything, it's relatively easy to work, it dries hard, and it can be sanded, drilled and machined. In some respects, it is easier to work with than a dowel or matchsticks. Just suggesting an alternative here. Either way will do the job nicely.

Bondo - which Phil mentioned, is a great wood filler. You will need to stabilize the surrounding material [we call it 'GLIT' AKA GLue and shIT]. Normal super glue works well for small areas - drip a bit while holding the baffle vertically to allow the CA to penetrate down and not into the grill cloth.

Russ

FWIW - while dowels and matchstick fixes have been around for ages, it is not a very good fix where the joint is under stress, as you are screwing into end wood. Changing to machine screws and tagnuts or just washers and lock nuts would do better in this case.....

Aurora wrote:FWIW - while dowels and matchstick fixes have been around for ages, it is not a very good fix where the joint is under stress, as you are screwing into end wood. Changing to machine screws and tagnuts or just washers and lock nuts would do better in this case.....

1+

Thank you all for the comments and good ideas. Leemo,I've successfully used the matchstick and glue trick on wood furniture from time to time, but this is 46 year old particle board and it's a bit too unstable and crumbly.

So far, I think I'm going to try to stabilize around the holes with "GLIT" as Geeze suggested, then fill with Bondo as Phil_S suggested. I went to the local auto parts store this afternoon and asked about binary putty: no one seemed to know what I was talking about. They did have 1 and 2 part Bondo, but the smallest size was one quart. Guess I gotta keep looking...

Aurora, I'm not sure how to go about " changing to machine screws and tagnuts or just washers and lock nuts" without disturbing the grill cloth which is quite a tight fit across the frame. Any suggestions would be appreciated.

Thanks again,
LDC

http://bondo.com/products/marine/bondo- ... 20131.html

http://bondo.com/products/marine/bondo- ... 20131.html

From my search smaller then 1 qt bondo wood filler is about same price so I would just get the 1 qt or go to a body shop and see if they will work with you.

Put some flat head machine screws in from the grill cloth side. 10-24 should be strong enough. You will have to countersink the holes to get the screw head flush.

John

I wouldn't get too worried about the grill cloth - I replaced a '63 super's baffle and the original grill cloth was nicely stretched out and went back on easily with 1/4" staples.

Don't think economy on this repair - think investment.

Russ

I recently bought a tube of this stuff: http://www.homedepot.com/p/RectorSeal-E ... /100124697 I haven't tried it yet.

It looks like the same stuff I bought in the auto parts store, but is about 10X the quantity and less money for the item. At this price, you have nothing to lose. I think I found it in the plumbing supplies.

Sorry, I didn't think about this when I first posted.

Would it be sacriligious to replace the baffle in a 69 Twin Reverb with new birch plywood?

I'm not a fan of particle board, especially if it's 40 plus years old and crumbling.

I guess a new plywood baffle would be considered a modification to a classic amp?

Long Distance asked about repairs. I think most of assumed he didn't want to get into replacement, which requires tools or friends with tools.

IMO, it's no big deal to put in a new one if you can move the grill cloth. No worse than a cap job. Routine maintenance.

I think the auto supply product is JB Weld.

just drill new holes from the back of the baffle cleats in different places from the original ones.

make sure the new holes are not where the edge of the speakers will be.

lay the baffle on the floor, put the cab flat on top of the baffle, and screw the old screws through the new holes into the baffle.

old mdf is pretty un-patchable.

good for another 20 years, anyway.

Bob