How to loosen rusty screw

[Richard]

I'm taking the seat off my backhoe to re-cover it. Seat back and seat bottom are both held on by four screws that screw into a threaded receiver (no nuts)

Machine is something like 29 years old.

Top of most of them looks very rusted. Flip seat pan over and the inside of them look almost new.

I've been spraying PB-Blaster on them a couple times a day for several days now.

Nothing happening yet.

I don't have.....(forget what it's called)...... I think it's called an impact screw driver? Might need to get one.

Any other tips or hints?

Screw is a simple 1" long machine thread, somewhere around 1/4". Nothing major in size.

 

[bigtiller]

One of those cordless impact drivers might be better, especially if the seat is spring loaded. But the impact screwdriver is cheaper and should work just as well if the seat is solidly mounted to the frame.

 

[Richard]

I've actually removed the entire seat from the machine so I can turn it upside down and get some pressure on the screwdriver.

Seat is deceivingly heavy. I'll probably need help hoisting it up to put back in the machine.

 

[Coyote machine]

An impact driver will likely just snap the head off the screw. Is it Phillips or straight slot screw? I'd use a suitable sized punch to bandg on the screw head with a hammer and punch. This may loosen up the rust, or if suitable, without likelihood of burning something on the seat use some heat on the screw head to see if that AND banging it with hammer and punch frees it up. Last, try grinding the head off with an abrasive disc on a grinder.

 

[DFB]

May have to soak for a much longer time to remove without any damage...I had a bear of time with two blind insert mounted stud nuts taking off the plastic shifter guide cover on my 4100 after 15 years this winter to do some body work. Thought they came loose after soaking but turned out they were just spinning inside the formed plastic shoulder. I gave up and ended up drilling it out right thru and used cap screws surface mounted to reinstall it. Looks fine to me and it wont be happening again

 

[Sawyer Rob]

Propane torch on the screw head, and be careful...

SR

I guess I was late with my answer... lol

 

[ultrarunner]

Heat has always worked for me with old equipment... use my welding torch with a small tip if I want pin point heat.

Don't know what to say in your case with it being a seat.

Years ago I bought a hand impact set... basically, it's like a screwdriver and you line it up perfect and tap the end with a hammer... either the screw will loosen of the head will snap... most of the time the heavier the screw... it will loosen.

 

[BigRol]

If you can flip the seat and an impact driver won't work just take a nut that is a tad smaller then the screw head, lay it on an mig weld it to the screw on the inside. PIA but works every time,

 

[Wagtail]

Would the old Tabasco Sauce trick work? :confused3: