Crusty rusty bolts and nuts

[JPA Cate]

Well done, Sune,

You got the job done. You know, with deformed nuts, you can actually file them down carefully, to the next size down, and get the 6 point socket on it just fine. I had to do that once. But I think the nut splitter saved you some time; and you did get the job done, which is what counts, in my book.

Show us pics of the chainplate when you get it out.

Ann

[Cadence]

Originally Posted by waterman46

That's strange, I thought WD40 actually was made for the job. Do you have a suggestion for something better?

My eldest son seems to think PS Blaster is better? I'll take the youngers word at 59 and owning a maintenance business.

If space permits, old school with a chisel to split the nut might work? It doesn't take massive blows just a sharp chisel and repetition.

[SailFastTri]

Originally Posted by Soton

Sorry Waterman my answer war a bit glib.

The thread in the tightening direction generally is not corroded and therefore the nut will tighten. Tightening the nut will put the bolt in tension. The thread vee acts as a stress raiser and a shear plane will develop and the bolt will fail by shear due to the tensile load.

Trying to undo the nut places no tensile load on the bolt. The bolt in effect acts like a spring. You have not got the same stress raiser effect as you have in tension and you are relying on the bolt to fail by shear only.

So yes trying to undo the nut may result in snapping the bolt or the shear force required to snap the bolt may be more than the shear force required to round the nut.

Not disputing what you wrote, but it should also be considered that further tightening with brute force on a bolt in a fiberglass or wood bulkhead would likely crush and damage the underlying substrate.

[Hoodsail]

See you've already been successful, but another option is use of what we call here in the USA, vise grips (aka locking pliers). Enables you to apply serious grip to anything (nut, bolt head, etc) so you can apply torque in whatever direction your working area allows. This tool comes in variety of size, grip teeth configuration. Disadvantage is it mars the nut/bolt head so you will not be able to re-use unless you reduce the size as Anne suggests. will be curious to see how your chainplates look. thnks

[boden36]

Good that it came out . You can also use a drill either to drill the end off the bolt, or alternatively, run a small drill down through the intersection of the bolt and the nut.
Keep increasing the size of the drill until you have cut the nut. Do this on two sides of the nut and it will come off with some gentle persuasion.

Regards,
Richard.

[Mike Banks]

I have been thinking--

I usually use an angle-grinder (you can get them with lithium batteries if you are away from power) and fitted with a stainless steel cutting abrasive disc.

The burglar's favourite tool. One then makes a cut right through the nut from the top down and from one side to the other. You can skim the bolt if you think you can preserve it, or you can simply go right through the end of the bolt if you are going to do the wise thing and replace all of them.

If you have not already removed the rigging, put a new bolt hand-tightened in place so the lot does not fall down as you punch out or unscrew from the outside, the rest of the bad bolts.

I would also agree that the chain plates may need replacement.




This is the quickest method for the rest of the bolts, if the nut splitter fails to work.
.

[sune]

The nuts and bolts came loose. A couple unscrewed, a couple snapped and a couple took a little more work. I will use best quality marine grade stainless when refitting.

The chainplates are fine. They have rust on the surface but aren't corroded at all.
I haven't cleaned them yet but have a look here.


My new problem that I don't know how to deal with, is where the chainplates were mounted. It has crumbled or broken apart. The wooden bulkhead behind seems ok, but the epoxy (if that is what it is) has fallen apart.
Is it epoxy?
How do I fix it before remounting the chainplates?


Thanks,
Sune

[boatpoker]

Originally Posted by sune

The chainplates are fine. They have rust on the surface but aren't corroded at all.
I haven't cleaned them yet but have a look here.

I disagree about the condition of the chainplates in your photo. Attached is an x-ray of a single pinhead size pit in stainless steel. The subsurface cavity is hundreds of times larger that the visible pit on the outside. Your choice.

[sune]

Originally Posted by boatpoker

I disagree about the condition of the chainplates in your photo. Attached is an x-ray of a single pinhead size pit in stainless steel. The subsurface cavity is hundreds of times larger that the visible pit on the outside. Your choice.

Ok. hmm, maybe I need to replace them then.

[Jim Cate]

Originally Posted by sune

Ok. hmm, maybe I need to replace them then.

They appear to be simple strap chainplates, and would be quite inexpensive to replace. In your place I'd do that, and if I intended to keep the boat a long time, spend the small increment to use 2205 duplex s/s.

Jim

[P3sailor]

Most likely too late with a response but will add my 2 cents worth.
AeroKroil works great especially with a little heat applied with a heat gun. If that doesn't work and you have the space to work, I would simply drill the the nut/bolt assembly until you are able to detach it from the shank. Start by drilling as close to center as possible with your smallest drill (say a #40) using plenty of lube for cooling. Work up in drill bit size until the nut basically falls apart or breaks free from the bolt. Remember, the rule of thumb when drilling steel or other hard metals is "Low speed, high feed!" Hope this helps.

[hellosailor]

I'm guessing someone at Kroil either died or retired, because now it is even available on Amazon! Wow, Kroil stepped into the retail and online markets! They finally figured out that mail-order-only just doesn't fly anymore. Nice to know they still don't waste money on advertising though. Makes you wonder what other treasures are out there.(G) I've still never seen a Kan on the shelf in a store, it should be up there next to the PBlaster racks. Or maybe they think the case-lot-only market is the one they want to pursue?

[Alan Mighty]

Originally Posted by sune

My new problem that I don't know how to deal with, is where the chainplates were mounted. It has crumbled or broken apart. The wooden bulkhead behind seems ok, but the epoxy (if that is what it is) has fallen apart.
Is it epoxy?
How do I fix it before remounting the chainplates?

Hej, Sune!

I have to agree with Jim Cate and Boatpoker: your 40-year old chainplates (i) deserve to go to the retirement home; (ii) would be easy to replace because they are simple to construct (no complex curves, no need to bring to a mirror finish because they are not decorative items etc); and (iii) if you chose duplex stainless steel (the 2205 grade of duplex ss that Jim Cate mentioned) would give you and whoever inherits your boat a guarantee of no crevice corrosion, no stress crack corrosion, and so on.

Concerning the bulkhead: it does look strange. My guess from afar is that you are looking at some surface coating that was applied to waterproof the timber bulkhead.

I doubt that it is epoxy, just because epoxy should not do that with exposure to water (the rust on your chainplates suggests some water and chloride salt exposure and not much exposure to oxygen - what you'd expect with wet stainless steel sealed off from air).

So it may be a coat of polyester resin, perhaps with some glass fibre reinforcing to give it structure. A flow coat. And I would have expected some bedding compound between the coated timber bulkhead and the chainplate metal.

I suggest you are going to need to remove that coating, so you are looking at clean and sound timber. And then re-coat with a waterproofing that would not deteriorate if exposed to water (polyester - depending on its molecular structure - can be permeable to water. Epoxy is very much more resistant to water. But epoxy is much more expensive than polyester resin, so a boat builder reaches for polyester instead of epoxy to control costs that might chase away boat buyers who do not realise that quality build is superior to inexpensive build).

If you can remove the coating back to clean sound timber, then I'd suggest coating the timber with a penetrating epoxy. And then perhaps more epoxy resin with structural strength provided with either some glass fibre cloth or glass beads in the resin. Then you should apply some bedding between your chainplates and that coating: an adhesive sealant (take your pick among silyl modified polymer, butyl rubber, polyurethane and so on) to guarantee that no water can sit in the interface between the coated timber and the chainplate.

At the minimum, you have to remove the unsound coating on the timber. If some of that coating is sound and resists strong abrasion, you might have to put up with its existence rather than expend much time and effort removing it.

Take care when you probe and remove that old coating. Especially if you abrade it away, with sanding or grinding apparatus, you may exposure yourself to airborne particles (glass fibres, resin, mouldy timber) that do not belong in healthy lungs.

[RaymondR]

If you can access the head of the bolts with an electric drill you can centre drill the head, starting small and increasing the drill size in steps, until the drill diameter matches the bolt diameter and the head falls off allowing you to drive out the now headless bolt with the nut still in place.

[Glenn.Brooks]

Another vote for Kroll. In the Pacific Northwest, USA, it can be found in any industrial focused hardware store, and at many marine stores.

50/50 mixture of ATF and acetone is the same thing as Kroll oil. Works the same,,nearly the same formulation, I have been told. Cheap, if you already have a quart of ATF and acetone. If not, then just buy Kroll.

Or, just grind the nut off with a 4” angle grinder. Then punch out the shank with a drift punch or screwdriver...