Siezed bolts

Egon · May 25, 2011

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

I'm assuming it would have to the same voltage and amperage that the original process required only applied in the opposite direction.

The 440 AC, being an alternating current, would only defeat the objective.

Baby Grand · May 26, 2011

Try putting a heat gun or lamp to the aluminum. Depending on the steel alloy used in the bolt, there's a good chance it's thermal coefficient of expansion is about half that of the aluminum, causing the aluminum to expand more than the steel, loosening the fit between them somewhat - maybe enough to get it turning with the wrench.

Gary Sweat · May 26, 2011

Coat the new SS bolt threads with anti seize compound or No-Ox and they won't seize up again. I have even used grease or motor oil and been able to get them out years later. Any bolt going into aluminum needs to be coated if you ever think you will be taking them out again.

Soundguy · May 26, 2011

I don't think I'd be going back in with SS fasteners after that again..

soundguy

MNBobcat · May 26, 2011

The guys who said to heat and then quench with penetrating oil offered a really good option. I've used that trick for years. It doesn't take a lot of heat. Its not the expansion of the metal (I don't think) that does it. I think what happens is the heat causes the already thin penetrating oil to thin even more and capillary action sucks the oil into the threads as it cools.

I use a propane torch the same as used in plumbing. You won't hurt the metal by lightly heating it. Steel should not be red hot, aluminum should not be glassy looking -- that's too much heat.

Soundguy · May 26, 2011

if the aluminum is glassy looking.. it's already puddling..

soundguy

Redbug · May 26, 2011

Also, I have always used anti-seize on the bolts that hold the foot onto the rest of the motor. That's a stainless set of bolts that goes into the aluminum housing. You have to get the foot off to inspect/replace the water pump impeller.

Chain Bender · May 26, 2011

Soundguy said:
I don't think I'd be going back in with SS fasteners after that again..

soundguy

Aluminum is definitely out!

Image this, two 1/2" thick plates of aluminum laying flat against each other. In each one in the same place there is a 9/16" wide slot about 15 inches long. On the bottom or inside plate, centered and affixed over the slot there is a 1" square piece of aluminum stock. This is where the 1/2" threaded holes are. The holes go completely through the 1" stock, are fully threaded and the 1/2" SS bolts go completely through this 1" stock and stick out ab out 1/4". The head of the bolts lay flat against the outside plate.

Now, if you don't know what a jackplate looks like it is basically an aluminum rectangal 15-20" wide and mine is 5.5" deep. It is bolted onto the boat and the motor sits on top of this rectangal. So, doing much from the inside with the motor on the plate is just about impossible. If I break the bolts off or tear up the threads I suppose I could just move up or down an inch or so on the inside plate and drill and tap a new hole. Since they slide, matching them perfectly isn't necessary so long as the match front to rear or left and right. Still, for an expensive (in my mind) jackplate, all this shouldn't e necessary.

tks for all input. Will let you know what I try and what works and doesn't.

CB

RoMad · May 26, 2011

I think you might be better off taking the motor off so you can get to what your working on. If you have something you can rig to for the motor maybe you can just unbolt it and leave it hanging very near where it was mounted but out of the way. Then you will have room to get creative with the bolts. Good luck, whatever route you take.

Soundguy · May 26, 2011

good luck for sure!

soundguy

SPYDERLK · May 26, 2011

Baby Grand said:
Try putting a heat gun or lamp to the aluminum. Depending on the steel alloy used in the bolt, there's a good chance it's thermal coefficient of expansion is about half that of the aluminum, causing the aluminum to expand more than the steel, loosening the fit between them somewhat - maybe enough to get it turning with the wrench.

OP, above is your best answer so far. Quicker heat would be a benefit tho, so I would use a propane torch with sheilding to prevent flame contact to any sensitive materials. Concentrate heat on the Al. Use penetrating oils. Use an impact wrench set low and with a cold socket to try to break it loose.
larry

Baby Grand · May 27, 2011

Chain Bender said:
Aluminum is definitely out!

Image this, two 1/2" thick plates of aluminum laying flat against each other. In each one in the same place there is a 9/16" wide slot about 15 inches long. On the bottom or inside plate, centered and affixed over the slot there is a 1" square piece of aluminum stock. This is where the 1/2" threaded holes are. The holes go completely through the 1" stock, are fully threaded and the 1/2" SS bolts go completely through this 1" stock and stick out ab out 1/4". The head of the bolts lay flat against the outside plate.

Now, if you don't know what a jackplate looks like it is basically an aluminum rectangal 15-20" wide and mine is 5.5" deep. It is bolted onto the boat and the motor sits on top of this rectangal. So, doing much from the inside with the motor on the plate is just about impossible. If I break the bolts off or tear up the threads I suppose I could just move up or down an inch or so on the inside plate and drill and tap a new hole. Since they slide, matching them perfectly isn't necessary so long as the match front to rear or left and right. Still, for an expensive (in my mind) jackplate, all this shouldn't e necessary.

tks for all input. Will let you know what I try and what works and doesn't.

CB

While you are at it, how about a picture or 2. I thought you were trying to unscrew a stainless steel bolt that is threaded into and aluminum plate - simple enough. But it sounds much more complicated from the above description. Even a hand sketch would help. I'm just trying to understand what's in the bolt "stack". It sounds like you have several thick aluminum plates clamped between the bolt's bearing surface (under the bolt's head) and the threaded hole?
How many elements in the stack, how thick is each element, what material is each element? How long are the bolts, and what alloy? If you do have a sizeable thickness of aluminum in the stack, you may want to buy a block of dry ice and forget about the heat gun. The solution is all about the problem.

Chain Bender · May 30, 2011

Baby Grand said:
While you are at it, how about a picture or 2. I thought you were trying to unscrew a stainless steel bolt that is threaded into and aluminum plate - simple enough. But it sounds much more complicated from the above description. Even a hand sketch would help. I'm just trying to understand what's in the bolt "stack". It sounds like you have several thick aluminum plates clamped between the bolt's bearing surface (under the bolt's head) and the threaded hole?
How many elements in the stack, how thick is each element, what material is each element? How long are the bolts, and what alloy? If you do have a sizeable thickness of aluminum in the stack, you may want to buy a block of dry ice and forget about the heat gun. The solution is all about the problem.

XXXXXXXXXX

Well, I've applied PB Blaster about 15 times in the past 5 days. Have put pretty good pressuer in both directions on the bolt heads. I dd get one of them to make a PING one time. I'm worried about twisting off one of the bolt heads more than stripping the aluminum threads. Pulling the threads would be the lesser pain than having to deal with 6 broken bolts.
I know that the last time the jackplate was adjusted it was tightened with an air wrench. I didn't do it. I was having some warranty work on the motor and they tore the bolts out of the first jackplate that was on it. They replaced it and now two years later I'm about to do the same. I do have one hole left in the motor mount itself that I can use to drop the motor down about an inch if I can't get all 6 of the bolts to break loose. Just didn't want to ahve to fool with that heavy motor by myself. Hurt my back last time I lifted it up onto the transom and mashed a finger when I set it down too! ;-)

Plates are 1/2" thick aluminum. High grade I would think. the block you see the tip of the bolt sticking through is about 1X1. The bolt appears to be about 2 1/4 long. From what I can see the only threads on the bolt are in the 1X1" block. The two 1/2" thick plates are squeezed between the bolt head and the 1X1" threaded block on the inside of the inside plate.

The whole jackplate from the right side.............

One of the 1/2" stainless steel bolt heads going through the two 1/2" aluminum plates and into the 1X1" square threaded aluminum block

looking up into the jackplate. The 1X1" square threaded aluminum block with about 1/4" of the 1/2" SS bolt sticking out of it.

tcartwri · May 30, 2011

Chain Bender said:
XXXXXXXXXX

looking up into the jackplate. The 1X1" square threaded aluminum block with about 1/4" of the 1/2" SS bolt sticking out of it.

Heat this block with a torch and the bolts will unscrew themselves. ( well not really, but it's not that big of a job )

Penetrating oils will accomplish nothing.

oldyellr · May 30, 2011

When it comes to penetrating oils, I've found that a 50/50 mixture of automatic transmission fluid and acetone works better than any of the big name brands. No kidding, just google it.

Soundguy · May 31, 2011

1/2" stainless bolts threaded into aluming.. right?

the threads will strip out before the heads twist off IMHO.

use an impact wrench vs a straight pull if you *think* you mighr be getting close to wringing a head off.

soundguy

BXpanded · Jun 1, 2011

Looks like the threaded 1" block will just drop out if the bolts break or strip. You can deal with it pretty easily then. Drill the bolts out, or just drill new holes above or below the existing holes. Then, put a new, longer bolt in with a nut on the back side of the block. No threads into the aluminum. If you use stainless bolt and nut, make sure you use "Never Seize" . My jack plate had 3/4" SS bolts and nuts. They were seized solid too. Used a pipe on a power handle and finally peeled all the threads off the bolts. Used "Never Seize" on the new bolts and haven't had any more problems.