juse
1 post
May 27, 2013
8:40 AM
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Hi All,
New here, and to harmonica in general. I have a JT-30 shell from the 1980s that I would like to powdercoat. It appears that the Switchcraft plug is pressed into the shell, I can't seem to get it out. My question is this... if I powdercoat the shell, will the temperature damage the insert of the plug? It appears to be either plastic or rubber. The powders I have are around the 450 degree range, so I just wanted to ask what the typical technique is when powdercoating a shell. Remove the plug and add a new one later, or just tape over the plug?
Thanks.
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Kingley
2685 posts
May 27, 2013
8:50 AM
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Do you mean the screw on connector at the bottom rear of the mic when you say "plug"? If so, then yes you'll need to remove it before powder coating. That connector is metal and probably some kind of plastic (maybe bakelite) in the middle. I imagine it would be likely to melt the middle part under those temperatures.
If it has an XLR connector then I'd remove the whole piece including the metal tubing it's inside of and then add a 2501MP like the old style JT30's had. Those connectors are easily available online. The part number is Switchcraft 2501MP.
Last Edited by Kingley on May 27, 2013 8:53 AM
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FMWoodeye
646 posts
May 27, 2013
8:53 AM
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I've had a fair amount of experience with powdercoating motorcycle parts back "in the day." I don't think a rubber or plastic component will survive the oven.
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juse
2 posts
May 27, 2013
10:00 AM
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That's what I thought, the heat would be too much. Didn't know if it was some type of phenolic material that could take the heat.
Anyone know how I can remove this connector? Looks like I will have to damage it to get it out. Are there replacements? Would they just be bolted in types, that would possibly work loose with use? Or can I salvage it?
Last Edited by juse on May 27, 2013 10:02 AM
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juse
3 posts
May 27, 2013
10:03 AM
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Sorry, I re-read your post, Kingley. Thanks for the part number. I will look into that. Is there a good way to remove the connecter, without damaging the shell?
Thank again.
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Kingley
2687 posts
May 27, 2013
10:16 AM
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If it's the XLR type connector and has the metal tubing on it (this is at the front bottom of the mic), you can just yank it out with a good pair of pliers. As it's only glued in place. If it's the screw on type connector (rear bottom of mic) then I'm not sure.
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juse
4 posts
May 27, 2013
10:26 AM
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It's the hi-z screw-on type. As long as I know I can't salvage it, I'm sure I can get it out somehow. Not sure how to press the new one in though. Might have to make a jig for the shell.
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Kingley
2688 posts
May 27, 2013
10:30 AM
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I'm sure if you ask over on Harp L someone will most likely know the answer.
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juse
5 posts
May 27, 2013
12:07 PM
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Thanks again, Kingley. When I look at the Switchcraft 2501MP connector, I see that the middle is an empty sleeve, where the wire is soldered. This leads me to believe that it may be able to handle the 450 degrees for 15 minutes for powdercoat, as a typical soldering iron temp is around 800 degrees, and the whole sleeve has to be heated up in order for solder to flow properly. I know it's not for 15 minutes, but it is obviously a heat-resistant material. Guess I could try it, and if it doesn't work, I could then pull it out.
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Kingley
2689 posts
May 27, 2013
12:30 PM
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The problem though is the plastic disc in the centre. With a soldering iron the central metal tab/spigot for the solder connection around that will act as a heat shield and protect it for the few seconds needed to solder the connection. With powder coating heat and the time factor though that will most likely melt.
I know that when Jeff Spoor and Johnny Ace do powder coating they remove everything from the shell before coating. It will give you a better overall finish and avoid any nasty surprises. The 2501MP connector is most likely either glued in or it might be tapped and screwed. If it's tapped and screwed then it should come undone fairly easily. If it's glued then it shouldn't be too hard to get out either. The only thing you need to do is work out a way to protect the threads whilst you're working on it.
Last Edited by Kingley on May 27, 2013 12:32 PM
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Greg Heumann
2158 posts
May 27, 2013
3:52 PM
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I believe that disk is phenolic resin, not simple plastic - and I suspect it would survive 450 though I'm not 100% sure. Only one way to find out......
One thing I CAN tell you with certainty is that if you remove that connector you will NOT simply be able to press another in and have it remain secure. And the hole is already too big to properly tap for the 3/8"-32 threads of a screw-on connector. Although I've seen lots of other approaches, the only one I know of that simply doesn't fail is the one I use - the hole is further enlarged and an internally threaded bushing is fabricated that presses into the new hole. The connector is installed in the bushing. It is invisible when done (except from inside the shell.) I do that work if you need it.
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/Greg
BlowsMeAway Productions
See my Customer Mics album on Facebook
BlueState - my band
Bluestate on iTunes
Last Edited by Greg Heumann on May 27, 2013 3:53 PM
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juse
6 posts
May 28, 2013
12:14 AM
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Thanks for the tips, Greg. I'm really curious now if the insert can handle the temps, so I think I'm going to try it with just wrapping the connector with heat tape and powdering it, but I ordered a 2501MP and a 3/8-32 tap just in case :) Guess I could try running a new 2501MP through my oven, too...
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Greg Heumann
2159 posts
May 28, 2013
11:22 AM
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Juse - you can't just tap that hole 3/8-32. It is already at 3/8" diameter which means hardly any thread depth will be cut and the connector fit will be very loose. Again, the only way to do that job right is to enlarge the hole, press-fit a bushing into it and drill/tap THAT for the connector. I can do that for you if you wish. But given the above I would test the new connector in the oven, not the powder-coated mic!
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/Greg
BlowsMeAway Productions
See my Customer Mics album on Facebook
BlueState - my band
Bluestate on iTunes
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