Cracked vintage fiberboard any ideas?

[Charlie Wilson]

Hello,
I have a 1967 Showman with a badly cracked board right where all the high voltage stuff is. The backing board is also cracked almost all the way across so that gets replaced. I thought I might drill holes at the end of each crack to keep them from going further. Don't know what else to do. Any ideas?
CW

[norburybrook]

you could run that very watery CA glue over the crack, capillary action should 'wick' it into the crack and secure it.


M

[10thTx]

I thought I might drill holes at the end of each crack to keep them from going further.

I think that is a good idea.

With respect, 10thtx

[Charlie Wilson]

Thanks guys. I just think any kind of gluing, because of the heat and the board wanting to warp, will crack eventually. I may drill the holes on either end of the cracks and if I don't feel good about that, do something kind of crazy like setting real small eyelets on either side of the cracks and running a jumper wire across. This really is not the part of the board I want to separate.
CW

[didit]

Based on photo would suggest using heat-tolerant pliant epoxy with layer or more of small "fish paper" patches to help spread & stabilize. Definitely avoid CA, which dries brittle and therefore handles heating poorly.

Best .. Ian

[Stevem]

You have no connection points down there to fret about have arcing issues with so really your only concern is to hold down that end of the board!

Get yourself a tad longer sheet metal screw and a metal washer for a number 10 machine screw and then a 1/4 inch washer and stack them up to clamp Bowen that end of the board and be done with it!

[martin manning]

I'm with Ian on using epoxy. Cut a circular or elliptical patch from fiberboard and epoxy it to the top surface of the eyelet board over the mounting hole. Before you put the patch on, run a small bead of epoxy along the length of the cracks.

[Charlie Wilson]

Hello, I finally got around to fixing the crack. I decided not to use epoxy because I thought it might make a board that probably wants to bend a bit more too stiff. I went with black Permatex instead. I glued a piece of fish paper under the backing board with the Permatex. Then I drilled holes on either end of the crack on the main board to keep it from going any further. Finally, I sandwiched some Permatex between the two boards to hold things but still let it be somewhat flexible.
CW

[jelle]

Nice repair!!

[didit]

Looks good. That Permatex RTV is tough stuff.

Best .. Ian

[gldtp99]

If you ever have problems with the glue repair job on your eyelet board----- Mojotone sells new non-Reverb AB763 eyelet boards that should get the Showman back into like-new condition:

https://www.mojotone.com/amp-parts/Fibe ... berboard_2

[Charlie Wilson]

Hello, Mojotone fiberboard is awful as is most of the current production fiberboard. I have had to remove several of them from builds and repairs due to conductivity issues.
CW

[harv1944]

I replaced my 70s twin microphonic conductive fibreboard with a proper glass fibre turret board. looks better and works a treat