Help with drilling out a stuck hex bolt

[Cadence]

Originally Posted by benzy

We have an old Whitlock steering pedestal where the top plate is held in plabe by two stainless steel hex bolts. These bolt into an aluminium throttle housing. Apparently they are supposed to be removed once a year and screwed back in with a healthy coat of tefgel or similar, but I reckon this hasn’t been done in about forever. They are totally stuck!

I’ve tried soaking with WD40, heating, tapping with a hammer, impact-type drill, etc. but to no avail.

So I think my only other option is to drill them out? But I’m not sure exactly how to do this?

Is it literally just drilling straight through the head down the longitudinal axis with a drill bit that is a bit smaller than the diameter of the bolt?

Any guidance would be great!

Ps I can access the underside and can use a nut and bolt, so not fussed if the thread gets messed up.

Cheers

SS keep the rpms way down and lots of "cutting" oil, both to keep the temp. down. Good luck!

[zboss]

Heat and transmission fluid can take a couple of days to work, over many many cycles. You can also try to alternate between freezing and heat. You can try heating the aluminum after freezing the bolt and then applying a better anti seize than wd40, like PB Blaster.

[hellosailor]

"then applying a better anti seize than wd40, like PB Blaster."
Ergh, neither one of those is an antiseize. I think you meant "a better penetrant" and WD-40 is not really a penetrant either. Great for squeaky door hinges though.(G)

[Cadence]

Originally Posted by hellosailor

"then applying a better anti seize than wd40, like PB Blaster."
Ergh, neither one of those is an antiseize. I think you meant "a better penetrant" and WD-40 is not really a penetrant either. Great for squeaky door hinges though.(G)

PAM works better on the door hinges at least it is a lubricant.

[CaptainJohn49]

I always have a set of left hand drill bits , torch and easy outs something will work. I’ve had bolts stuck so bad I had to drill them out so far that only the bare threads were left which I had to remove with a dental pick. After removal I cleaned the threads with a tap. Maybe I should have gone to dental school.

CaptainJohn49

[sy_gilana]

Use Chemistry...go Breaking Bad on it!


Make a saturated solution of Ammonium Aluminum Sulfate commonly called ALUM.


Heat it to about 180f drop the part in. The steel will dissolve. (Use an Aluminum pot)

[Dougtiff]

How about creating new bolt holes if unable to remove old fastening's, i.e., cut old bolts flush with top of rim, drill and tap.

[Siberian Sea]

They make a special tool/kit called an «*easy out*».
Basically it’s a kit that has these small tube guides and you choose the one that’s the size for the hole you wish to drill. The kit also has the drills. The guide makes sure you drill straight into the stuck bolt and NOT into the threads.
Once the hole is drilled into the bolt the kit supply’s special insert rods that you tap into the hole. The rods have teeth cut into them so once inside the hole the grab the bolt. Then also supplied in the kit is a special sleeve that slides over this toothed inserted rod. The sleeve will not turn on the rod but only slide on and off. The sleeve is designed so you can put a wrench on it.
You turn the sleeve that over the shaft that inserted into the stuck bolt. The entire assembly should then turn out.
I have one of these kits and it’s works wonderfully to remove broken off bolts.

[boatman1]

Previous post asked how hot the aluminum throttle casting (female thread) got warmed? If you can get it hot enough (w/o setting the boat afire) the bolt can be turned. Lot's of heat. If you can get to the bottom of the aluminum casting, use a whole saw just larger than the bolt and cut the bolt area right out. Drilling in stainless will drive you to drink.

[BruceS]

Watched a Honda outboard mechanic remove 4 stubborn SS bolts out of the aluminium water manifold cover on a 90hp recently.
His main tool was one of those little gas torches like for silver soldering or Chef's use... Got them all out in the end. Just takes time & patience.

[um saudade]

This may be the place for the arc welder. Grind the heads round enough that you can get a carbon steel nut to just go over the old bolt head. You want to have about half the nut filled with the old bolt and the top open.

Protect everything from splatter and weld the bolt to the nut with stainless rod. Use fairly high amps and get good penetration into the old bolt, then bring the fill to the top of the nut. The stainless will bond to the nut well enough and the process of welding will expand the old bolt like crazy, effectively breaking the corrosion bond.

Wire feed welder will work too but you need the amps to get the heat and penetration.

Let it cool and turn it out.

[seabreez]

Originally Posted by benzy

We have an old Whitlock steering pedestal where the top plate is held in plabe by two stainless steel hex bolts. These bolt into an aluminium throttle housing. Apparently they are supposed to be removed once a year and screwed back in with a healthy coat of tefgel or similar, but I reckon this hasn’t been done in about forever. They are totally stuck!

I’ve tried soaking with WD40, heating, tapping with a hammer, impact-type drill, etc. but to no avail.

So I think my only other option is to drill them out? But I’m not sure exactly how to do this?

Is it literally just drilling straight through the head down the longitudinal axis with a drill bit that is a bit smaller than the diameter of the bolt?

Any guidance would be great!

Ps I can access the underside and can use a nut and bolt, so not fussed if the thread gets messed up.

Cheers

The drilling of stainless has to be done very slowly. The best drill bit to drill stainless is a concrete bit. Yes concrete bit. The tip is carbide and will stay sharp as long as you drill slowly and keep it lubricated to keep the drill bit cool. I would drill down only the thickness of the head and then remove the cover and try to grab the bolt with vise grips and try to loosen the bolt to remove it. Do not use easy outs with stainless. If room allows it, you will probably need to drill oversize and re tap to the next size larger.

[nic26]

Originally Posted by hellosailor

Absolutely. Easy-outs have a reputation for breaking and making a mess, but you are drilling into softer aluminum with a steel easy-out, so it should work very nicely. There are some brands that allow you to drill, reverse the bit, and extract.

You could also try an impact hammer, about $20 often with the right bits. Or if you can get some dry ice conveniently, cover the plates with a slush made of broken dry ice in alcohol. Freezing contracts the metals, often breaks corrosion without any danger from flames. If you repeat that 2-3x then use the impact hammer...almost everything can be moved.

You can also get and use "ice spray" that cools down anything to -20 °C immediately. Makes metal into a piece of cake

[GrowleyMonster]

Stainless steel into aluminum. Not a good idea without some neverseize or other antiseize compound. Easy outs not needed cause you still have a head on the bolt, right? You could take an impact wrench to it, but possibly you could crack the aluminum. Can you grind off the head, leave the bolt in, rotate the fitting just enough so that you can drill a new hole, then tap the new hole and use new bolts? That is what I would do.

[masonc]

Grind a slot in the head with dremel or grinder with a cutting blade. You can put a large screwdriver in that and a wrench on the shaft to turn it