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.

 

[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

 

[Sockwell]

Don't be afraid to try the drill. A lot of folks have the misconception that all SS fasteners are hard. However, often the application only requires corrosion resistance and not strength. In those cases, 18-8 grade SS fasteners are used because they are much cheaper than 308 or 316. (MSC-Direct prices for 3/8-16 x 1" SHCS - $58.66/C for 18-8, $145.87/C for 316) 18-8 fasteners are only slightly harder that Grade 2 steel fasteners.

I also agree with the guys above. I don't pretend to have seen all penetrants, but of the one's I've used, Kroil is easily the best.

 

[KENSFM]

Stainless steel threaded into aluminum is never a good idea. You will probably ruin the threads in the aluminum trying to get them out. You will probably have to re-thread to the next larger size if this is possible in the piece you have. If you do fix it be sure to use never-seeze or similar thread lubricant on the new bolts.
Good luck,
Ken

 

[jonyyuma]

Stainless steel threaded into aluminum is never a good idea. You will probably ruin the threads in the aluminum trying to get them out. You will probably have to re-thread to the next larger size if this is possible in the piece you have. If you do fix it be sure to use never-seeze or similar thread lubricant on the new bolts.
Good luck,
Ken

I agree completely, there are a lot of these connections and kroil and pb blaster are pretty good. Next if messed-up then retap, and lube the threads.I've not had to break em loose after-salt emmersion..

 

[Soundguy]

sometimes I even paint them afterwards, as you can always blow them off with carb cleaner to remove..

soundguy

 

[Egon]

Reverse the chemical reaction that caused the problem. Apply the proper voltage and wait.

 

[ole farmerbuck]

Here ya go OP
Google Deal

 

[Chain Bender]

Reverse the chemical reaction that caused the problem. Apply the proper voltage and wait.

Would that be, 12V DC or 440V AC? Recon holding a 14 guage solid wire until it cherried would be long enough?

There's 115 gallons of gasoline and 3 gallons of 2 stroke oil pretty close to where I'd be applying votage and waiting. Oh yeah, did I mention it was a fiberglass hull as well? Porbably gonna smoke a little if it lights off! ;-)

CB

PS: 600' of 1/2" triple braid nylon rope too.


Thanks for all the recommendations guys. Will start small and then break out the cutting torch if necessary. Hopefully I won't tear out the threads on the aluminum plates, but if I do it is going to be one pain in the but to get them out. I say that because I'll have to remove the 300 from the plates to work on them. Oh well!

 

[Soundguy]

save the cutting torch.. stick to propane.

aluminum don't get that wet look.. it goes from solid, then just slumps and falls away

ps.. if the ss is seized into the aluminum from galling.. I suspect you have a 90% chance of damaging the aluminum threads.. looking at the realitive strengths of aluminum and ss.

kind of like a wood screw into pine... wood gives way first...

still.. good luck..

soundguy

 

[Stihlrunner]

I have removed 100's of broke and seized bolts as a mechanic.

Every bolt is a little different but one of my practically failsafe methods is to heat the offending bolt (doesnt have to be glowing) and then spray with General Motors Heat Riser Penetrant (remember when cars had chokes?!) or JB80 from Justice Brothers. Let it soak several hours and repeat a couple times. You will be amazed when you pull the boat how the penetrant coated the threads.

Another choice would be one of the freezing penetrants made by Gunk and a few others. It supposedly freezes the bolt and then works in penetrant. I used it a couple times with good results.

Whatever you do, don't rush the process! If you go slow, use heat and quality penetrant and a quality wrench or socket you will be fine.

 

[dieselbeef]

if you can cut the heads off to get the bolt out of the way then you can drill them..ss is drillable if ya take yer time and use good oil and a cobalt bit. cut and x in em with a die grinder and chisel the head off..then drill em out..if you can thru bolt em on the reinstall id do that...evena ss nut galled onto the bolt is better than ss bolt corroded into alum...heating and then cooling with penetrating oil might work if you heat the bolt super hot and then cool it with oil..but in all honesty its gonna be a real pita no matter what...