Best Method for loosening stuck bolts.

[cprodave]

A couple weeks ago I busted off a stainless Head Bolt while investigating low compression on an engine. Luckily the other 5 Head Bolts came off with no problem (I had soaked all 6 Bolts with penetrant, but didn't use propane torch to heat the Head). So I was able to lift off the head, penetrant soak the busted Bolt another week or 2, then heated with torch and ViseGripped out the bustet bolt.

Call me "gun shy" but now working on another outboard 8hp Model (B)E8BACD(E) I am removing the powerhead. I have removed the 4 rearmost underside Bolts (going through Lower Cover up into Cylinder/Crankcase Block--2 Bolts on Starboard side, 2 bolts on Port Side) without any problem. Now I am trying to remove the 1 forwardmost underside Bolts (1 on each side) which are less accessible, i.e. If I break off either bolt it will be very difficult to drill the bolt and use an EasyOut to extract--there is no way to get a drill bit in there at a correct angle.

So...a couple questions:1) in general when dealing with stuck/corroded stainless bolts (which have formed an intermetallic corrosion byproduct with either aluminum or plain/carbon steel) is it best to apply loosening torque/pressure using a Hand Impact Driver (which is shock and torque simultaneously), or is a socket/wrench better (applying slow/steady torque)?
2) penetrant that seems to work best for me is Liquid Wrench, although Lucas Penetrant Oil ("Home and Shop Oil") in spray can seems good with bubbling/effervescent action. I cannot get Acetone and Transmission Fluid (both old and new style) to mix--they're like oil and water although this combination is supposed to work great. Has anyone else had problem with Acetone/ATF not mixing? I have some FreezeOff spray but haven't used it aggressively or extensively.
3) is it better to apply torch heat to the female threaded area or cold (upside down Keyboard Cleaner spray) spray to the male Stainless Bolt? Now that our home/shop locationis forecasted to get subfreezing next couple nights (and months) is there any advantage to setting the outboard outside overnight (i.e. below freezing) then propane the female thread area on the Engine Block prior to wrenching?
4) is a Heat Gun set on High Heat as good or better than a Propane Torch or Butane mini-torch? I've read of mechanics heating stuck etc to red-hot, then wrenching--not sure that is a good idea. I tried my butune mini-torch on one of these stuck bolt areas, after 2 minutes or so it barely heated the target area due to large thermal mass of powerhead...

Any tips forum members can give based on first-hand successes (or failures) would be much appreciated.

 

[Chris1956]

Heat is good. I have heated bolts and then sprayed them with a penetrating oil. As they cool, they tend to suck some of it into the bolt passage. It is good to heat the block to help it to expand and loosen from the bolt shaft.

Also, use a 6 point socket or box wrench and loosen them just a bit, and then retighten them. Repeat that loosen-tighten a few times, and they can sometimes be worked out.

 

[cprodave]

Heat is good. I have heated bolts and then sprayed them with a penetrating oil. As they cool, they tend to suck some of it into the bolt passage. It is good to heat the block to help it to expand and loosen from the bolt shaft.

Also, use a 6 point socket or box wrench and loosen them just a bit, and then retighten them. Repeat that loosen-tighten a few times, and they can sometimes be worked out.

Thanks Chris. I will try spraying after heating and the loosen/retighten trick. BTW thinking about this some more, it seems if I accidentally shear one or both the of the Bolts off then I will be able to slip/pry (depending on bond strength of Exhaust Gasket) the powerhead off of the Lower Cover. So it wouldn't be such a bad situation after all. Is my thinking correct?

 

[Chris1956]

It is never good to break a bolt. Mostly because they usually break at the first thread, which is usually flush with the block. Then you are drilling a SS or Steel bolt, in an aluminum casting. That is very difficult to do well.

Take your time, use lots of penetrating oil and heat and say a few prayers.

 

[gm280]

There are so many "good" ways to remove stuck bolts on the internet. One that I've seen that seems to work well is using the torch and of course penetrating oils and take a hammer and peen the head of the bolt to help fracture any corrosion before you start trying to remove it. And I too really like Liquid Wrench myself, but everyone has their favorite. Slow and easy and turn any movement back and forth as you proceed. Don't go for the slight movement ability and muscle it out. It can break so easy doing that. Back and forth and it will work... JMHO

 

[racerone]

Nature can be cruel to nuts and bolts.------One thing that can be done on new motors is to remove certain bolts one at a time.---Remove lower unit and water pump -----Dip threads in sealer and re-install.----Keeps water out of the threads and nearly eliminates corrosion products from jamming thing up.

 

[Scott Danforth]

50%/50% mix of acetone and ATF is my go-to penetrating oil.

however as racer indicated, sealing the bolts prior to corrosion is best. I use permatex #3

 

[F_R]

You ain't seen nothing yet. Wait till you get hold of a few salt water motors. You will throw out all the mouse milk potions and get out the blue wrench (the oxy/acetylene torch). You gotta get it hot. Very hot. Very, very hot. Propane and mini torches don't get it.

 

[cprodave]

Well, I had 50% success. On the first bolt I used lots of heat from heat gun, applied penetrant, let it soak, let it cool, reheated/repeated several times over a period of 2 hours or so. Also peened the head to vibrate and aid penetrant movement. Then I applied CRC Freeze Off for around 20 seconds. Used my Manual Impact Wrench to get maybe 1/4 turn loose. (another 10 second shot of FreezeOff during the 1/4 turn) . Then I did the tighten/loosen routine with a 6 point socket/ratchet multiple times, applying penetrant (Liquid Wrench, ATF, Lucas Penetrant Spray) often. This was eventually fully successful on removing the 1st (of 2) Bolts.
Then unfortunately I may have gotten a bit cocky/overzealous on the 2nd Bolt. As I recall I didn't do as many cycles heating, dripping on Penetrants, cooling, reheating, repeating etc. I did use the CRC FreezeOff for around 20 seconds again. But Big Mistake I made was that after I got around 1/8- 1/4 turn loosened with the Manual Impact Wrench I continued to use The Impact Wrench instead of switching to a 6point Socket and Ratchet with the Back-and-forth technique. I probably hit this Bolt 100-150 times with the Impact Wrench. The stress/pounding on the Flange of the Exhaust Housing to Powerhead Bolt ( p/n 325095 or 333676) was just too much--the hex head separated from the Flange. In hindsight I believe the downward pounding of the socket rim attempted to bend the flange downward (this is a Flanged Hex Head Screw) as soon as minor space was created by the screw turning out 1/8-1/4 turn. The combination of turning the hex while simultaneously impacting down on the unsupported Flange created tiny cracks that eventually propagated to complete failure. The Flange is not meant to be pounded on, I guess. UGGH! On Bolt #2 I should have followed the same exact process as closely as possible to Bolt #1.
So now I have 2 choices: Method #1) try to drill through the Flange into the Bolt Shaft and use an EasyOut. Not easy to access or drill, plus the Torque required to loosen/ back out might shatter the Easy Out. However, if this technique Fails it would still be possible to perform Method #2) Grind off the Flange leaving a straight Bolt Shaft which is a slip fit through the Exhaust Housing but threaded into the Powerhead. Then if the Powerhead can be lifted off, Use more heat/oil/FreezeOff and Visegrips to extract the bolt stub. Problem I foresee with this is the Exhaust to Powerhead Gasket might be well bonded/adhered--often a gasket like this has to be overcome by twisting one part from another--easy to do if there is only this one bolt--but DriveShaft is seized into the Crankshaft on this motor (which is one of several reasons I am doing this disassembly). Similarly, if Method #2 fails then I could problaby still do Method #1.

So...any input on what to do? thanks again to All for input on the Art and Science of Undoing Stuck Bolts.

Scott Danforth, is your 50/50 mix immiscible (like oil and water)? Mine is, and problem I have it that the liquids separate before I am able to apply them to the desired area. How do you dispense/apply?

Racerone, thanks for the good idea on the sealants, I have a couple other outboards that need this done.

F-R, I know what you mean about saltwater. All my engines were/are used in saltwater, although I rinse/flush after every use there are still so many fasteners that form severe intermetallics.

 

[cprodave]

Not a great photo but the the broken-off Hex Head portion of the Bolt is lying to the left. The Bolt with Flange still attached is to the right. The Flange is likely not thick enough to grab with Visegrips, if i can even access...

 

[Scott Danforth]

no way to get enough heat with a heat gun. the best heat guns in the industry will get the surface temp to maybe 400 F. you want that bolt to about 700-900F

 

[cprodave]

no way to get enough heat with a heat gun. the best heat guns in the industry will get the surface temp to maybe 400 F. you want that bolt to about 700-900F

Scott, thanks for this info. This is the level of detail that is really helpful to me. I moved in April...have a friend in our previous town that has a "blue wrench"...and he is always willing to help.

 

[gm280]

Is it possible to weld on a nut on top of the broken bolt? The welding will certainly heat up the bolt as well. Just an ideas...

 

[dingbat]

Lube with your favorite penetrating oil. I keep a can of PB blaster around the house. Use kroil at the shop

Take a good size ball peen hammer, small head to the bolt, and give ball peen a good smack or three with a second hammer.

The idea is not to beat or bend the bolt, but too shock stress it. The harder the bolt the better this process works.

Welder/machinist by trade. If shock doesn’t work, I twist the head, drill and extract. Chase threads with tap.

Eight out of 10 times its quicker than screwing around with heat and no chance of distorting the part.

Upon assembly loctite blue (sealer) on all ferrous hardware. Never-seize if a stainless on stainless connection

 

[cprodave]

Good idea to weld a nut on top of the remaining Bolt Flange as this would allow Back-and-Forth method. Also good idea to use a lot of heat from a oxy/acetylene torch. Unfortunately I'm not sure I have any way to get access to either a welder or a torch (a friend of mine in last town we lived in has both, but he is 4 hours away and due to COVID would be hesitant for me to visit--he has multiple pre-existing conditions). So unless I get a brainstorm about how to get access to these tools (EX; local auto repair I frequent probably has both) I am going to have to Dremel off the remaining Bolt Flange, hope I can lift the Powerhead off, then use lots of penetrant and whatever heat I can get (using Propane Torch, etc), peening, and ViseGrips back-and-forth method. One positive about Dremeling off the Flange is that removing the Flange might allow better access for penetrant which has been blocked by the flange so far.
Any other ideas/advice?

 

[cprodave]

Photo showing broken Bolt remaining Flange in back at left, Hex nubbin in middle, and a good Flanged Bolt to the right.

 

[ct1762@gmail.com]

i beleive i had mentioned "free-all" in another post. i know, sounds stupid as most guys have a product they stick with, but that stuff is incredible. they key is it literally dissolves rust/oxidation over night, then heat the crap out of it, whack it a few times, get one of those reverse-thread sockets, tap it on (should be tight now it's hot) and i use a small impact. but yeah, sometimes they snap. sucks. the nature of the beast with salt water stuff unfortunately.
As for the torch: I only ever use the cheap handheld BUTANE ones that go clikkity-clack from amazonia. they are actually awesome, and some have a giant flame same as a larger torch. a red-hot bolt is a red hot bolt, no matter what you use.

 

[cprodave]

I couldn't get the bolt red hot with my butane torch. Nor could i grip the remaining Flange with longnose ViseGrips. Flange was too thin. Any small grinder that was small enough to access removed material at a snail's pace. As a last resort i did discover my cordless drill (smaller housing than my usual 3/8 corded drill) was able to drill out the Flange. This allowed the now-headless and now-Flangeless Bolt to slip through the Lower Cover. Lifting the Engine Block off the Lower Cover i was then able to apply Liquid Wrench with ATF to the Bolt in area that Flange had covered. I let lubricant soak for a day, the Visegrips removed Bolt Easily. But all in all i learned a hard lesson about patience and using the back and forth method.

 

[cprodave]

Photo added. Pencil is pointing to the culpret Flange Bolt.

 

[ct1762@gmail.com]

its scary even those adapter gaskets weld themselves to aluminum! Lucky us i guess. finishing up an xp-100 rebuild project. powerhead adapter gasket was so welded on i had to stand on the gearcase hanging from engine hoist and hit it with a rubber hammer to get it free. she popped off hard. good thing i wasn't wearing flip flops haha. motors.