Ideas on straightening a bent chassis on this Pro Reverb

[Sleet]

I'm working on my brothers SF Pro Reverb and after removing the chassis realized that it somewhere along the way had taken a nasty hit right above the intensity control (see picture) I'm going to be going through and refreshing caps and the like as it has never been serviced and seen little use. I know what I need to do to push the front of the chassis back into position, just not what kind of tool(s) I could use to accomplish the job.

Some sort of turnbuckle arrangement might work with a block of wood to push off of?

[Enzo]

I would call it patina and leave it.

Did someone put the pilot light escutcheon BEHIND the panel ?

[dmartn149]

What about a C clamp? Place a piece of angle iron against the front, with spacers on each end to hold it away from the face. then use a c clamp to pull the face out.

[Sleet]

Yeah, It's an odd looking pilot light and the bulb is also missing, so I'm not sure what to think. I may just replace the whole pilot light assembly.

[Leo_Gnardo]

Yeah, It's an odd looking pilot light and the bulb is also missing, so I'm not sure what to think. I may just replace the whole pilot light assembly.

There's a bright chrome(?) plate decorative washer that was on many of the silver face amps, often missing after 40 or so years. Dang if I know where to find a replacement, it's not part of the pilot fixture. I don't recommend replacing the pilot fixture unless it really is defective. The deco washer fits between the jewel and the fixture. I suppose if it was dropped during a long ago bulb replacement, and rolled away under the sofa or something, that's why so many are missing.

[nevetslab]

Bessey makes a small bar clamp that allows you to reverse action so it can expand instead of clamp. Also the larger Jorgensen Pony Clamps that fit onto 1" pipe will allow the moving stop to be reversed, and can be used to expand. I suppose you could set up a mounting scheme to hod the two ends of the chassis fixed on a bench, and then use a 2 x 4 with a 5 pound sledge or similar heavy hammer and give it as many whacks as it takes. I'd be fearful of that approach, though. I'd do it with an expanding bar clamp. I use one to expand the wooden cabinet of Vox AC30-6/TB's to get the chassis out of the cabinet.

You also may need to drill & tap a couple #4-40 holes at the pilot lamp end to get the face plate tied down. I've had to do that more than once on our rental gear.

[Sleet]

What about a C clamp? Place a piece of angle iron against the front, with spacers on each end to hold it away from the face. then use a c clamp to pull the face out.

I'm going to try one of those reversible wood working clamps that can work as a spreader. Hopefully, it will be strong enough to move the sheet metal back into place.

[Enzo]

The "chrome washer" the pilot screws into is actually the socket fixture. What I clumsily tried to describe is it looks to me like someone installed the socket onto the chassis, and THEN mounted the decorative panel over top of it. The chrome washer you see is really the outer edge or lip of the socket housing. That lip is what holds the panel tight to the chassis. Face plate, yes, better word than panel.



Once the face plate gets bent it is hard to straighten it without taking it off. Mounted to the panel, there is no way to overbend it to let it relax back to straight. I hope that sentence makes sense.



Remember, when that top edge bent backwards, it stretched the metal on the top ledge. When you bend it back, that top edge is now slightly longer than before, and so will wrinkle a bit. Hopefully not enough to cause trouble, but be aware of it.

[Tom Phillips]

The attached photos show the tool I made to spread Fender chassis from the inside. It was made from a turnbuckle I had laying around at the time. In actual use I remove the switches and connectors from the rear panel and clamp on a strong piece of angle iron to stiffen the rear panel. It also works well to "C" clamp the angle iron / rear panel assembly to the edge of the work bench. This, of course, is to prevent the rear panel from bending when the turnbuckle is tightened to push the front panel back in place.

Cheers,
Tom

[drewl]

I've seen the faceplate pop over the trim washer on several amps.

Probably happened when it got bent.

A couple blocks of wood and a vise might straighten it out a bit.

[52 Bill]

I've seen a lot of the silver face amps that came with a large chromed washer that held the faceplate down under the jewel. The actual lamp holder was screwed directly into the chassis.

The turnbuckle idea looks like a great tool to build, the large reversible clamps don't fit down into the chassis unless you dismantle the panel mounted controls.

[Chuck H]

The only thing I would add to the turnbuckle or clamp idea would be a block of wood across the inside, back of the chassis along the folded edge to distribute the force. Wouldn't want to end up bent in on the front and out on the back!

[Bloomfield]

I was thinking the same thing; a strip of hardwood with a shallow saw kerf in it would stop it from slipping off as well. You could drill a shallow hole to seat the end of the turnbuckle screw too.

If the faceplate is coming up a bit in the corner you could try a little two-sided tape in there. If you get the right stuff it can be incredibly strong.

[Tom Phillips]

Man! I thought I was clear in post #9 between the narative and the anotations added to the photos. I'll take a photo of the complete set up the next time I need it. I just need to stay focused on a bunch of other tasks right now.

[Sleet]

Thanks Tom, This is what I was thinking of when I mentioned a turnbuckle earlier in my postings.