Seized Stainless Nuts - Nut Splitter?

[KWKloeber]

My opinion is I'd grind the head of the bolt off from the top with a 4" angle grinder. Keep a wet rag to control heat.  All mess and filings will be on the top side not the inside.  The washer will be sacrificed as it will keep you off the fiberglass.  A nut splitter big enough will not fit next to the chain plate. Stainless is so much harder and resilient than low carbon steel nuts such as what nut splitters were made for.  I wouldn't waste the time and money on the nut splitter.

If I did that approach, rather than try to cut it flush, with my thin stainless cutting blade I'd first grind straight down (on bolt slot, if it's positioned right), then with a cold chisel split the head (stainless is brittle), clean up as needed to drive the bold down.

-kk

[J_Sail]

Ken,
Regarding the difficulty in drilling from the topside, while I agree it isn't trivial, I wouldn't compare it to the challenges of the example you are apparently thinking of, namely removing a bolt from something like an engine block (you mentioned overdriving and tapping fresh threads).

In your automotive case you would have needed to drill out the whole bolt, which I agree is tricky; in Steve's case he only needs to weaken the junction between the head and the bolt sufficiently to cause the head to shear off. Then the bolt drops thru and can be removed from below. In this case the drill bit doesn't need to be the exact full diameter of the bolt and the centering accuracy doesn't need to be exact. I agree that stainless is a bit harder to work with, but I have done this successfully before in other settings. 

I don't know enough to say what's the best approach, but I would consider this one along with the others.  I do agree with the other posters, though, that the heat is totally manageable for any of the approaches.
BTW, sorry for my ignorance on the specifics of the Catalina, but what's the bolt diameter?

[patrice]

Hi,

I think Jsail idea is a nice one.
It will be a lot easier to work from the top than upside down.  You will have more control on your tools.

You could use the idea of a shield to protect the suround.

Use a small drill bite to start a pilot hole, then use bigger one.  Use a good drilling lubricant when drilling.  Will save the bite and ease temperature.

This is the same principle to remove pop rivet.  Drill the head.

Or, from the top again, use a 4" grinder.
You could grind Slowly the head of the screw.  Since the space is not great, use the grinder as if you wanted to cut the existing slot widder and widder, you will eventally eat the whole head.

Good luck

[Craig Illman]

I'm going to make the same recommendation I made in a referenced thread. I used my cordless Ryobi 3/8 drive impact wrench on the acorn nut. I'd try that first, before starting to drill or cut anything.

My two cents........

Craig

[J_Sail]

I believe his initial post said he had already tried an impact wrench without success.

[Craig Illman]

Ah, missed that. Maybe some C4 then?

[Sailing Steve]

Craig - I can't stop laughing aloud!!!! Love the C4 comment!!!

I'm going to get at the job as soon as the season is truly done, and I'll update the results starting with how/if the nut splitter worked, then move up the ladder of suggestions, hoping to avoid the C4 though.

[Sailing Steve]

SUCCESS!

After trying everything else including multiple brands of penetrating oil (none of which showed any migration into the threads) over multiple applications, impact wrenches, heating the nuts etc, it came down to the Dremel and the nut splitter - Credit to Jim Hardesty who was the first response to the initial post.

When I initially tried the nut splitter on the chainplate acorn nuts, it didn't work - It only left a slight indentation on the nut from the nut splitter blade.  Only after I used the Dremel with the fiberglass metal cutting wheel (about one 1" wheel and 20 minutes per nut BTW) to remove the dome of the acrorn nut, did the nut splitter work - I suspect the dome gave the nut too much strength over an area not touching the nut splitter blade.

It took a box wrench as a snipe on the handle of my ratchet to have enough turning torque to turn the nut splitter in enough to split the nut, but it worked on all four nuts that I was trying to remove.  When they split, it is with a bang and a few sparks!  In each case I only had to split one side of the nut, and the remainder would either fall off with a few light taps of the hammer, or would back off using the socket set as the bolt threads were not damaged.  The nut splitter was a low end, inexpensive C$12.50 (On sale %0% off - about US$2 LOL) made in China model to boot.

The Dremel was easy to handle in the tight space, preventing any collateral damage, and the heat produced by the cutting action was also easy to control as it didn't remove near the amount of metal that my angle grinder would have.  Although I could have cut right through the nut/bolt with the Dremel, it would have taken longer, and used more cutting wheels, plus more chance of over heating the surrounding area.

Thanks again for all of the suggestions, and I hope my experience helps someone in the future.

Steve

[Ron Hill]

Steve : Here is what I'd try:
1. Grind off the round head of the acorn nut until the threads and the bolt shows. 
2. Then use a Dremal tool and cut a slot in one side of the nut.
3. Take a common screwdriver tip and insert it in the cut and spread the nut till it opens

A few thoughts

[Ron Hill]

Guys : You can't use a nut splitter on an acorn nut until you grind off the rounded head of the acorn nut!!

A thought

[Stu Jackson]

SUCCESS!>>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>>>>>>>>

Thanks again for all of the suggestions, and I hope my experience helps someone in the future.

Steve,

Thanks for the very thorough report.  I have the same issue with two of five acorn nuts on my  port handrail.  I have already removed the bungs from above, and tried to hold the top of the bolt with a flat blade screwdriver and a vice grip, while using a ratchet socket down below.  I tried, my "very strong large buddy" tried.  No luck.

I started with the dremel, with a new blade, it's a battery powered model.  Not much luck, and in 20 minutes all I got was a bit of a few shiny spots on the acorn nut.  I'll try again tomorrow.

Does anyone know if there is a cutting tool similar to a dremel blade that I could use in my real drill?  The clutch in the dremel seems to stop the blade from turning when I apply enough pressure that would seem to be needed to actually start cutting the acorn nut's metal.  It could be that a "plug in" dremel could be "stronger" than my "toy" of a battery powered dremel.

Any ideas?

[KWKloeber]

Stu
When you say Dremel blade, specifically?  There's different types - what are you looking for?
I've picked up both 1/8" and 1/4" shank carbide and diamond grit cutters of different types.
Some from eBay, some from Aliexpress, some from HF.
IIWMB I'd invest in a good rotary tool which is more compact than a drill  - I have an older Dremel but I think my RTX is a better rotary tool.

[tgsail1]

Stu- I had this problem years ago. Forewent the Dremel tool in favor of an angle grinder with a cutoff wheel. A bit of overkill, but the angle grinder gives you pretty good control.
http://c34.org/bbs/index.php/topic,7265.0.html

[Ron Hill]

Guys : The best tool that I found to grind off and cut metal is a hi speed grinder (10,000 rpm) IF you can get it in the space?  Otherwise you need a Dermal Tool.

Harbor Freight has a cheep 4" Hi-Speed one that I've tried and is still working 10 years later!!

A few thoughts

[Stu Jackson]

I'm making progress.  I was able to remove one of the acorn tops this afternoon.

It's truly amazing how much a charged battery in the Dremel tool can make.

I'll either buy or rent a nut splitter now.