Loosening a thight screw

ttf_sirisobhakya · Post by **ttf_sirisobhakya** » Wed Jan 24, 2018 8:35 pm

My horn has an asjustable thumb plate on the trigger. 1 year has passed but I have not yet made use of it, due to very tight screw. It is tightened from the factory. I cannot (or haven't yet been able) to turn it by hand, and I haven't dare using plier on it due to fear of deforming it or the trigger stem. The screw is made of nickel silver, has plain head and serrated rim, kind of like watch's adjusting knob.

How should I try turning it? One way that just pops inside my brain is applying cold things to the head so that the metal will contract, but I don't have much confidence in that.

Thank you for your answer.

ttf_BGuttman · Post by **ttf_BGuttman** » Wed Jan 24, 2018 8:41 pm

If you have one of those jar openers that's a sheet of rubber, put it over the knurled knob and then use pliers. You won't mar the finish that way.

Take a look to see if they used some thread locking lacquer (usually a red dot somewhere in the place the screw contacts the plate it's screwed in. If there's lacquer, you can loosen it with some nail polish remover or lacquer thinner.

If all this sounds like Greek, take it to a tech, who will take about 30 seconds to do the job.

ttf_sirisobhakya · Post by **ttf_sirisobhakya** » Wed Jan 24, 2018 9:01 pm

Thank you! I will try it.

ttf_Driswood · Post by **ttf_Driswood** » Thu Jan 25, 2018 8:12 pm

Corrosion Cracker from Ferree's. I understand it will get into a space as small as a millionth of an inch. I used it all the time to loosen stuck screws at school and in my wood shop.

Jerry Walker

ttf_Radar · Post by **ttf_Radar** » Fri Jan 26, 2018 6:16 am

I would try penetrating oil like Liquid Wrench or WD-40, I would avoid pliers I've twisted the head right off screws that way and had to drill them out an tap the hole, not something you want to do on a musical instrument. Use the grippy rubber pad thing to get a better grip on it but avoid pliers.

ttf_Radar · Post by **ttf_Radar** » Fri Jan 26, 2018 6:16 am

I would try penetrating oil like Liquid Wrench or WD-40, I would avoid pliers I've twisted the head right off screws that way and had to drill them out an tap the hole, not something you want to do on a musical instrument. Use the grippy rubber pad thing to get a better grip on it but avoid pliers.