67 Year Old Head Bolts

[LaqueRatt]

Working on an old Sportwin 10. Any tips on getting them out? I'd really like to avoid snapping them.

 

[dwco5051]

Working on an old Sportwin 10. Any tips on getting them out? I'd really like to avoid snapping them.

 

[Crosbyman]

soak the bolt heads with penetrating lubricant for a few days if worried

work slow be patient
I have never had broken bolts on oldies so you may have no problems.

you can try a freeze spray to break the bond or heat the bolt heads if they can be reached and apply a release agent so the capillary effect can allow some to penetrate. Clear as water silicones seems to work ok.

sometimes a 1/4 inch impact driver going clock wise for a short burst then CCW may break the bond but don't overdo it. go manual if worried

 

[Scott Danforth]

I found that a light snack with a brass hammer on the bolt heads does wonders

 

[dingbat]

Penetrating oil and a 1/2” pneumatic impact gun is my go to. Turn air pressure down a bit to loosen up any crud in the threads before going full force.

If that doesn’t loosen them, I use two ball peen hammers to break it loose.

Place the small end of one hammer on the head of the bolt and hit the face of the hammer with the other.

Mechanic friend turned me on to using a “bolt breaker” tool with an air hammer. Works like a charm

 

[racerone]

On a fresh water motor they usually come out no problem.----Done more than one 67 tear old motor.-----Pouring boiling water over the block/cylinder head area will heat the area of the threads.---Expands the aluminum and releases the grip.

 

[LaqueRatt]

Thanks for the prompt replies. I have both a 1/4" hex impact and a 1/2" pneumatic, but think maybe I'll try to work them loose by hand first after employing the loosening techniques already mentioned. I'm not really expecting trouble, but my personal life lessons have proven to me that there is always that ONE damned bolt........

 

[saltchuckmatt]

Thanks for the prompt replies. I have both a 1/4" hex impact and a 1/2" pneumatic, but think maybe I'll try to work them loose by hand first after employing the loosening techniques already mentioned. I'm not really expecting trouble, but my personal life lessons have proven to me that there is always that ONE damned bolt........

Any salt evidence or not ...if not sure post pictures.

Your talking about the "red headed stepchild" she ate the apple, so that's a tough one sometimes.

My go to is heat and crayons now... definitely taught this old dog new tricks. Old guys around salt water motors say heat the bolt, not the surrounding areas it threads into...heat, cool and repeat. Over and over and over until it starts to move.

Praying is an accepted mechanical operation.

 

[Crosbyman]

heating the bolt allows a heat transfer to the engine's bolt threads and body
in effect releasing the bind on the bolt itself . This is what happens in the
ball-and-loop physics demo. The ring expands when heated and allows the ball to pass the inside circumference of the loop. thankfully aluminum expands more than bolt steel !

The applied heat to the bolt does not shrink the bolt to break the bind. The engine's aluminum body expands outwards .....releasing the bolt.

my understanding anayway

 

[Mc Tool]

Thanks for the prompt replies. I have both a 1/4" hex impact and a 1/2" pneumatic, but think maybe I'll try to work them loose by hand first after employing the loosening techniques already mentioned. I'm not really expecting trouble, but my personal life lessons have proven to me that there is always that ONE damned bolt........

Just me but I dont like using impact drivers on corroded stuck fasteners. There is a skill learnt of previous disasters where one can tell the difference between a bolt that is actually unscrewing and one that is twisting to breakage....you loose that advantage with impact drivers.......you will however get better at removing the broken bolts.

 

[dingbat]

Length (in inches) = Length (in inches) * Δ Temperature (in °F) * ε (in / °F).

Steel = 0.0000065” / °F.
Aluminum = 0.0000128” / °F.

Pouring boiling water (212F) on 70F aluminum would expanded the hole in the aluminum 0.0018” x hole diameter….0.375 x 0.0018 =0.00068”

This assumes you have enough energy to heat the mass of the entire hole up to temp. Would be very hard to do given the thermal conductivity of aluminum.

 

[saltchuckmatt]

heating the bolt allows a heat transfer to the engine's bolt threads and body
in effect releasing the bind on the bolt itself . This is what happens in the
ball-and-loop physics demo. The ring expands when heated and allows the ball to pass the inside circumference of the loop. thankfully aluminum expands more than bolt steel !

The applied heat to the bolt does not shrink the bolt to break the bind. The engine's aluminum body expands outwards .....releasing the bolt.

my understanding anayway

In the case of salt, that's exactly right. Your trying to break it up or break it down.... Braking the bond.

I also use the cold spray to speed up the process. In the end, I heat up the female side of the equation and it's not always in the threads but also in the shank. You can tell how or where the salt was if you break one.

On the impact? No, I always use a hammer and a drift. Shock value is all I want.

Standard screw heads like the oil drain plug I do use a screw driver impact tool.

I will have to say, lately I've haven't spent much time trying to save the bolt, but just wrench them out carefully, and let them snap if need be. I now weld a matching nut on and spin them out that way.

I've had success but the jury is still deliberating.