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How to unscrew driver from horn?

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How to unscrew driver from horn?

PostPosted: Tue Jan 12, 2021 12:06 am
by mikehende
Hey guys, I am trying to unscrew a 1" driver from a horn in my garage but I guess the coldness in there has it frozen maybe. I don't want to tap the driver, is there any SAFE way to loosen it please?

Re: How to unscrew driver from horn?

PostPosted: Tue Jan 12, 2021 7:08 am
by resistorman
I've run into horns that look like they should come apart but were actually one piece. Assuming this is not true, warm it up gently with a hair dryer. Tapping cold materials is not recommended.

Re: How to unscrew driver from horn?

PostPosted: Tue Jan 12, 2021 11:31 am
by ef37a
Had this problem with air rifles.

Yes, apply heat, hair dryer, heat gun (carefully!) I used boiling water on guns. Once hot, squirt on WD-40. This penetrates the thread and I always had 100% success.

Never seen Ed on Wheeler Dealers?

Dave.

Re: How to unscrew driver from horn?

PostPosted: Tue Jan 12, 2021 5:17 pm
by Sam Spoons
The Coefficient of expansion of aluminium (the horn) is about twice that of steel (the thread on the driver) so it shouldn't take too much heat to free it up, possibly even taking the assembly into the house for a couple of hours might do it. Plus Gas or similar 'penetrating fluid' is probably better than WD40 but WD40 is worth a try first if you have some to hand.

Re: How to unscrew driver from horn?

PostPosted: Tue Jan 12, 2021 5:42 pm
by ef37a
Sam Spoons wrote:The Coefficient of expansion of aluminium (the horn) is about twice that of steel (the thread on the driver) so it shouldn't take too much heat to free it up, possibly even taking the assembly into the house for a couple of hours might do it. Plus Gas or similar 'penetrating fluid' is probably better than WD40 but WD40 is worth a try first if you have some to hand.

Oh! You obviously have not seen Ed Sam! Aluminium on steel will of course corrode and if bad enough the assembly might never come apart without damage. If dry heat does not work try hot water, I think some of the Al/FeO compounds are soluble.

IF you do succeed refit with a smear of Vaseline or Copper grease NOT silicone grease.

Dave.

Re: How to unscrew driver from horn?

PostPosted: Tue Jan 12, 2021 6:06 pm
by mikehende
Thanks guys, I am going to bring it inside, leave it for couple hours to try to get to room temp then use the blow dryer. I am thinking when replacing with the other driver to use this?

https://industrialsafety.com/loctite-23 ... UsEALw_wcB

Re: How to unscrew driver from horn?

PostPosted: Tue Jan 12, 2021 6:11 pm
by ef37a
mikehende wrote:Thanks guys, I am going to bring it inside, leave it for couple hours to try to get to room temp then use the blow dryer. I am thinking when replacing with the other driver to use this?

https://industrialsafety.com/loctite-23 ... UsEALw_wcB

Use it if you have it, otherwise check the bathroom cabinet or the fridge for some Turkey fat!

Of course, it MIGHT have been cross threaded!

Dave.

Re: How to unscrew driver from horn?

PostPosted: Tue Jan 12, 2021 6:24 pm
by Sam Spoons
ef37a wrote:Oh! You obviously have not seen Ed Sam! Aluminium on steel will of course corrode and if bad enough the assembly might never come apart without damage. If dry heat does not work try hot water, I think some of the Al/FeO compounds are soluble.

IF you do succeed refit with a smear of Vaseline or Copper grease NOT silicone grease.

Dave.

True enough Dave :thumbup: as a dinghy sailor I'm well aware of the affects of dissimilar materials in a good electrolite (say salt water) :blush:

Re: How to unscrew driver from horn?

PostPosted: Tue Jan 12, 2021 6:48 pm
by mikehende
No turkey fat here so will get that lubricant for Sunday when we will be comparing the 2 Different drivers finally.

I brought one horn inside to replace with the Peavey 22a Driver:

https://i.postimg.cc/hPx9sqr2/IMG-2371.jpg

https://i.postimg.cc/KY9LjcG8/IMG-2372.jpg

Will run the blow dryer in another hour from now, report back.

Re: How to unscrew driver from horn?

PostPosted: Tue Jan 12, 2021 8:15 pm
by mikehende
Well, the blow dryer method worked guys, as soon as the driver got to room temp with the blow drying it turned easily. thanks!

Re: How to unscrew driver from horn?

PostPosted: Wed Jan 13, 2021 5:54 pm
by Martin Walker
Excellent news - thanks for letting us know Mike! :clap:

(moves hairdryer into audio tool case)


Martin

Re: How to unscrew driver from horn?

PostPosted: Wed Jan 13, 2021 7:13 pm
by mikehende
Yeah but now screwing on the Peavey 22a drivers I just got, they are not screwing in all the way due to the extra adapter piece I am thinking. The JBL measure 3/4" from base to tip and the Peavey measures a full 1"

https://i.postimg.cc/tJ7MrhtG/IMG-2388.jpg

https://i.postimg.cc/fW6GHrFH/IMG-2389.jpg

Wondering leaving the Peavey as it is will be ok?

Re: How to unscrew driver from horn?

PostPosted: Wed Jan 13, 2021 7:31 pm
by Sam Spoons
I'm not sure, The horns are Peavey or JBL? The original horn driver is the JBL? Just looking at the new pics the horn looks as if it is plastic not ally BTW?

Re: How to unscrew driver from horn?

PostPosted: Wed Jan 13, 2021 7:36 pm
by mikehende
Peavey MF1-X Horns: https://assets.peavey.com/literature/ma ... 301017.pdf

Original driver for the horn is the 22A, no specs available for this but the next updated version is the same:

https://peavey.com/manuals/80300843.pdf

I am trying to get the guy who sold the drivers to me as he has the same horns.

Re: How to unscrew driver from horn?

PostPosted: Wed Jan 13, 2021 7:42 pm
by Sam Spoons
If the Peavey horns were built for those specific drivers they should be fine* there appears to be a gasket on the end of the threaded portion implying that they are meant to fit up against the throat of the horn. The JBL may not have been fitting right up to the throat which might compromise the sound (though I doubt it would be noticeable). I'd be inclined to fire them up and have a listen, as long as you don't drop them downstairs the slightly less secure physical mounting shouldn't be an issue.

* Unless they have different versions with different throat lengths for different horns?