Rebuilding Ohm model C's

This is a project I did a while back. I picked up a pair of Ohm Model C's in pretty rough shape. The surrounds were rotted and the cones had partially popped out . One woofer cone had a detached spider and damaged and frayed tinsel wire.

The first step was repairing the woofers. I shimmed the cones and used a strand of fine wire and wrapped it around the frayed tinsel wire. Then I used a soldering iron a let a little solder flow onto the damaged area. You can see the repaired area on the end of the right wire. Once that was done, I used some epoxy glue in a small syringe to re-attach the spider back to the cone. That worked well as the syringe could get into the basket to apply the epoxy.




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Step two was re-foaming the woofers. I used a white glue that came in a re-foam kit and glued the center edge first and let that sit overnight. Once that was dry I glued the outer edge. After the glue tacked up a bit, I removed the shims and made sure that nothing rubbed by carefully moving the cone up and down. Then I let that dry overnight as well. Glued on some new dustcaps and they were done.



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Pics of the refoamed woofers.

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I gave them a quick sound check after mounting back in the cabinets. They sounded pretty good.

Step Three was refinishing the cabinets. They had water damage on the top and I had to remove the the top piece of veneer from one of the cabinets. It looked like Ohm used contact cement, so I used a heat gun to loosen the cement and peeled off the damaged veneer. I used a putty knife and the heat gun to scrape off the contact cement. The cabinets were prepped by sanding with 100 grit paper.



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I chose a quilted maple veneer which I found on E-Bay.

I used the Titebond II glue and iron method to attach the veneer. I rolled on a good coat of glue on the cabinets and the veneer with a three inch roller and let that dry until it was just clear. When gluing the veneer, I used push pins and held the veneer flat on a thick piece of cardboard so it didn't curl up. Once the glue turned clear, I positioned the veneer and used a iron set to a high cotton temperature. A block of wood 1 inch square by 6 inches long with smooth, rounded corners helps while you're adhering the veneer. Follow up with the block after the iron-- using it to push down on the veneer especially around the edges.



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Veneer on the front of the cabinets

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I trimmed the veneer using a router with a flush trim bit. It gives a nice squared off edge.

I sanded the veneer lightly with 120, then 150, then 220 grit paper and finished with 4 coats of Formby's semi gloss tung oil, using some 00 steel wool after each coat except for the last one. I painted the baffle boards black.

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The grills were still in good shape-- a few frayed corners but this type of material is easy to fix. It's the open weave stuff, almost like burlap. A needle and thread to hold the frayed strands down.

The total cost for this project was about $55

Maple veneer - 30
Titebond II Glue - 7
Surrounds - 7
Black paint - 4
Roller- 2
Epoxy- 5

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thats sweet. very nicely done all around.

Sharp, real sharp. nice job.

elroy

Great job. Well done.
They look beautiful.
Congrats, and enjoy.

This post has been edited by clint e. on April 19, 2007 05:26 am

Awesome stuff, just awesome. Looks better than new to me.

Jorge

didn't know they made box speakers....great job.