How to smooth out the bumps?

BradS · Jun 26, 2018

I've just acquired the Spotmatic shown below. As can be seen, it has a big dent on the top of the prism housing. I was thinking that I'd try my hand at pounding it out...what could go wrong?

My question is, after I get the top off, how does one pound out the bump? Is heat used ? I'm imagining a ball peen hammer, a sturdy flat surface and maybe a steel dowel?

Sirius Glass · Jun 26, 2018

If it does not affect the photographs I would leave it alone.

BradS · Jun 26, 2018

Sirius Glass said:
If it does not affect the photographs I would leave it alone.

Seller says it it has no effect. He just dropped (pun?) it in the mail this morning so, it'll be a few days before it is in my hands....
but yeah, I am inclined to leave it alone and use it as is.

***(EDIT) but I didn't buy this one to use it...I bought it specifically to see if I could do a tolerable repair and if not, to scavenge for useful parts.

David Brown · Jun 26, 2018

Sirius Glass said:
If it does not affect the photographs ...

"Only dropped once!" (actual for sale ad)

shutterfinger · Jun 26, 2018

BradS said:
Is heat used ? I'm imagining a ball peen hammer, a sturdy flat surface and maybe a steel dowel?

Its soft aluminum, sit it in the sun for an hour or two.
Hardwood works well for straightening metal. Lay it on a wood base and use hand pressure on a wood dowel or strip 1/2 inch wide from outside edges to inward of the dent. A light tap with a hammer may be needed to get the edges correct as will a straight edge of the strip of wood.

Berkeley Mike · Jun 26, 2018

Wood dowel on a rubber matt, like a car floor mat, not neoprene. Start gently from the outside, softer edges of the dent, and work slowly into the creases. Don't rush. Be prepared to tweak it a bit as you try to put it back on as the metal has been stretched. Good luck.

shutterfinger · Jun 26, 2018

Hard rubber is likely OK, soft rubber is a NO. Wood, even hardwood has some give which is usually enough to help hold the metals shape and prevent it from bending the opposite direction.

John Koehrer · Jun 26, 2018

It's chrome plated brass not aluminum. I don't believe I've seen a top or bottom cover made of aluminum.

sissysphoto · Jun 26, 2018

I have had pretty good success knocking out dents. I ve got several black Nikkormats that I straightened out looking beautiful and without painting. But you have to do it skillfully. Your dolly surface whatever it is must be mirror smooth and your tools but be flat, smooth and matched to the dent. I was fortunate enough to have acquired an old cabinet of letterpress furniture, which provided me With many sizes of hammering tools. For little round dings I had on hand the extender that came with a set of 1/4 inch drive socket wrench set. I d lay the part flat down on my dolly, which for me is a smooth sheet of 1/4 inch copper. The place the end if the extension tool directly over the backside of the ding, and give a skillful pop with my ball peen. You'll notice I used the word skill twice. Anybody can have it. Thinking is the biggest part of it. To just go whacking on a dent will make a mess of it. Any tool can be used, selected for it's size, shape, and smoothness. Easy does it.

Theo Sulphate · Jun 26, 2018

I assume you know how to get the top off. That circular ring, or whatever it's called, around the wind shaft (under the film counter) is a royal pain. I have an adjustable wrench with two pointy ends that fit in the ring slots, but even then I find it very difficult to remove the ring.

BradS · Jun 26, 2018

Theo Sulphate said:
I assume you know how to get the top off. That circular ring, or whatever it's called, around the wind shaft (under the film counter) is a royal pain. I have an adjustable wrench with two pointy ends that fit in the ring slots, but even then I find it very difficult to remove the ring.

The fastener (slotted nut?) under the screw that turns the wrong way? Yea, that one is tough. The manual kinda hints at a special tool...I improvised by using two jewler's screw drivers held in a crescent wrench and still managed to booger it up. I'm thinking the special tool must look something like a two headed screw driver...or a screw driver with a deep 'V' cut into the business end...?

Kino · Jun 26, 2018

https://www.ebay.com/i/253147784292?chn=ps

or

https://www.ebay.com/itm/Bent-DSLR-...-Open-Tools-/162118084998?hash=item25befda986

The curved blades would more likely close down better for the smaller diameter.

Theo Sulphate · Jun 26, 2018

This is what I have:

https://c.76.my/Malaysia/profession...a-repair-open-2-iezuaaf-1710-04-iezuaaf@2.jpg

It's great for the shutter speed dial, but still makes a mess of the circular ring. I know one repair tech that makes his own custom tools from simpler objects, much as you have done.

shutterfinger · Jun 26, 2018

There's likely a big orange box near the op. https://www.homedepot.com/b/Lumber-...wood-Hardwood-Boards/Oak/N-5yc1vZchznZ1z0jphw
For a one time use or very infrequent use a piece if 1/2 x 1 inch 1 foot long and a 1x6 board 3 feet long and a pack of 220 sandpaper will make a suitable surface to work on. The skill is not to hit too hard and not tap the piece past the surface of the wood.
Brass is a soft metal and covers are usually thin, .020 inch / .5mm; .025 inch / .6mm thick.

BradS · Jun 27, 2018

Thank you to all who responded for your advice and encouragement. Good folks like you are why I love this place.

Sirius Glass · Jun 28, 2018

shutterfinger · Jun 28, 2018

Wow us with the results.

How to smooth out the bumps?

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