Siezed bolts

[Chain Bender]

I have six 1/2" stainless steel bolts siezed in a threaded aluminum hole. They are on a jack plate rated for a 300 HP outboard motor.

I need to lower the jack plate about an inch due to some additions to the bow of the boat. The SS bolts are siezed up in the aluminum from oxidations and a lot of salt water. I've put every thing I can think of to free or loosed the oxidation but can't. The aluminum is pretty hard and I can't apply any heat for fear of making it brittle.

Anyone have any suggestions?

thanks in advance,
Chain Bender

 

[tcartwri]

You wont need that much heat, and that's pretty much the only way you're going to seperate those parts.

 

[ole farmerbuck]

Kroil. It works great but not real fast. Needs soaking time.

 

[Chain Bender]

Kroil. It works great but not real fast. Needs soaking time.

xxxxxxxxxxxxxxxxx

never heard of it. where can I find it?

tks

 

[Bartcephus]

PB Blaster and Kroil can be found at most automotive part stores. PB Blaster works well too.

 

[ole farmerbuck]

Kano Kroil Penetrating Oil and Bore Cleaning Solvent 8 oz Liquid - MidwayUSA

 

[beeforty]

If you put the "HOT WRENCH" to it aim the flame at the bolt heads and heat up them not the plate, they will stretch in length and maybe loosen up.

 

[dieselbeef]

likely yer gnna ruin the holes once ya git it out..we deal with this problem alot at wrok and its never good

 

[Scooby074]

I agree with dieselbeef. If its that galled, id almost bet the aluminum will be damaged.

Id apply heat, either with a torch or with one of the new induction heaters to prevent the possibility of damaging the aluminum or having open flames near that area.

Try kroil first though, its good, just might not be THAT good

 

[Soundguy]

heat won't make the aluminum brittle.. probably more like ductile.

in any event.. I hate SS fasteners.. once thay gall.. you are SOL.. that aluminum plate will have the threads pulled out fast... I'd have used galvanized or cad plated fasteners.. not SS.

heat em, and quench with the penetrant oil... drilling out the centers will be a bear since they are stainless... yet another reason not to use them where not absolutely needed. for what was mounted.. and the size of fasteners.. gr2 would have been MORE than sufficient, and very easy to drill out..

well.. once you get them out you can go to 5/8 or 3/4's I guess,

soundguy