Suggestions to release seized thread

[1969Mk3Spitfire]

Not Triumph related but hopefully I can call upon experience of the forum.

I have an M12 steel thread seized into a die cast aluminium bracket. There are 2 of these and they are the clamp screws holding an outboard motor to a transom. Thread is protruding either side of the bracket.

So far, over 2 days, I’ve sprayed liberally with Plus Gas and a couple of cycles of pouring boiling water over the castings.

I’m as yet reluctant to use a gas flame and also mindful that die cast aluminium is not malleable and will easily fracture.

Current thinking is to reapply Plus Gas for about a week and then try again.

Any other suggestions would be most welcome?

 

 

[RogerH]

Have you got a clear picture of the assembly.?

 

Roger

[Pete Lewis]

wrap something to keep the release agent on site to gain some soak   coke cola works well  and vinegar  the acid may eat the alloy corrosion out  

Pete

[NonMember]

As Pete said, the important thing is to keep the release agent in contact so it can slowly penetrate. Also, it often helps to vibrate the thread. If you have a battery drill / screwdriver with a torque setting, turn it down low, fit the right socket, then give it a couple of minutes of rattling each way before re-dosing the release agent. You're not trying to force anything, just to encourage release agent penetration.

[1969Mk3Spitfire]

Many thanks.

The picture shows one side of the transom mounting bracket.  The other is a mirror image. I've had the engine in storage for more than 10 years.  The screws will not budge, even with a bit of help from a 10 inch Stilson.

I was thinking about fashioning a 2l milk bottle into a shallow bath and using something like paraffin.  Intrigued by the thought of using an acid, vinegar.  How about brick cleaner, hydrochloric acid, I use this once per year to clean marine growth from a non-ferrous, nickle-aluminium-bronze propeller. Perhaps a bit too strong for die cast aluminium?

Appreciate your thoughts.

[trigolf]

How about spraying the thread with aerosol freezer spray. It might help the plus gas penetrate?

[daverclasper]

I have used a decorating heat gun on alloy, get it hot so it expands, and use penetrating fluid, may take a few goes but has worked well in the past.

Have been wary of hot gas flames on alloy myself?, though I think folk do use it?

 

[Ian Smith]

if it's a marine based clamp, then it'll be (most probably ) LM2 grade Aluminium. Be a bit wary of too much heat at or about the threaded portion of your clamp. A little known fact about Aluminium is due to its alloy properties, it actually shrinks before expanding.  The old maxim is:- "if it won't go one way, it'll go the other".  Put the clamp into a vice and tighten with the  threaded portion uppermost. Ensure the thread is scrupulously clean, and well lubricated. Using a small hammer and a block of wood, lightly tap the offending area, with the wood block behind the threaded portion.  The force is about the same as cracking an egg. The block of wood is there to absorb the force of the tapping action. I don't know what releasing fluid you're using, but WD40 or Plus-gas should normally suffice. Try the clamp: One way, or the other?  If you do have a little bit of movement, then oil that portion only, and repeat. I used to make up a mixture of LM grease & WD40, and brush it on. it might take a while, but you should end up with a working clamp. 

Finally, if you're using heat, beware of too much. Sledge hammers will also mean 'tears before bedtime'. 

Best wishes,

Ian.

[Ian Smith]

2 hours ago, Pete Lewis said:

wrap something to keep the release agent on site to gain some soak   coke cola works well  and vinegar  the acid may eat the alloy corrosion out  

Pete

Does that actually work? I understand that the latest fizzy is toned down considerably.  I've used old mineral-based engine oil, such as GTX. 

Cheers,

Ian 

[JohnD]

WD40 is USELESS as a penetrant.  As a product it's as overhyped as the American's "Marvel Mystery Oil"!!  "Coke" is just ridiculous!

Ive been impressed with "Innotec Deblock Oil XS".   To try and keep anything soaking the part is a good idea, or else, frequent (every hour?) little squirts.

John

[1969Mk3Spitfire]

I do have a heat gun, if needed, and it’s a good shout, better than a gas torch.

This morning, I’ve dug-out an old pressure cooker. Both brackets just fit inside. I’ve cooked them for just a few minutes as a first trial. One has moved about 5-10 degrees but made a dreadful noise as it ground to a halt. The other one stubbornly has thus far refused to budge.

My latest snake oil is model aero engine fuel. Methanol should penetrate as well as anything else and the mixture has light oil suspended within.

I’m told that patience is a virtue. Gas, 2lb hammer and 14 inch Stilson still in the toolbox.

[Colin Lindsay]

6 minutes ago, 1969Mk3Spitfire said:

One has moved about 5-10 degrees but made a dreadful noise as it ground to a halt.

Then re-oil, especially if you can see even the slightest bit of new thread, and tighten again. If the seal has been broken, albeit slightly, then get oil into the threads you can now see; if you oil them and retighten it will carry oil back into the housing and lubricate the next movement. Repeat, and repeat, and repeat, but it will work eventually. Use proper lubricating oil not paraffin-like WD40.

[JohnD]

Yes!  Work it to and fro!    

If at any time the bolt starts to squeal, STOP! It may be about to seize and break!   Reverse, oil again, wait, try again.

John

PS Pressure cooker, good idea!   Did you cook in some oil?

[1969Mk3Spitfire]

It did squeal, unfortunately.

I just used plain water for the first trial of the pressure cooker.  Oil is a good idea, thanks.  Should I use virgin or extra virgin olive oil 😃 My wife is out all morning so I think I'll give it another try.

Many thanks for all of the replies.  I appear to have two of the most repair and maintenance intensive hobbies with cars and boats. 

[1969Mk3Spitfire]

Pleased to report that all is now well, screws turn in and out easily over their entire length without even a hint of binding.

15 minutes in a pressure cooker with water and a spoonful of cooking oil. 👍

Black and Decker workmate together with a few wooden packing pieces held the bracket firm and 10 inch Stilson turned the screw. 

I planned to put in fresh oil and some fuel to see if it starts but rain stopped play.  Well, it is Manchester and it has a reputation to uphold.

Thanks to all for help, suggestions and advice.

[JohnD]

O. M.G.    

Now, we have "Marvellous Mystery Olive OIl"!

But the idea, and the successful execution of the project, makes me think of getting an old pressure cooker, to ensure matrimonial harmony.   Lots, on eBay!   Then I could put, well, anything in it!

John

[Colin Lindsay]

34 minutes ago, JohnD said:

Now, we have "Marvellous Mystery Olive OIl"!

That's why my chips never stick together in the air fryer... but matrimonial harmony....hmmmm. Sidelight lenses through the dishwasher, fine, but drying painted brake calipers in the oven... I thought she was unreasonable. It's VHT paint so needs VHT, for goodness sake.

[Peter Truman]

BBQ Colin! I suggested the kitchen oven to cure the VHT on the Calipers, recently when I did the daughters Spit type 14's Wife's statement "over my dead body", daughter (her Spit) DaaaD no way! so BBQ at 160 from memory for 1 hr, but let the VHT paint dry for several days first.

A friend did my exhaust manifold in the BBQ after painting with BBQ/Pot black several years ago (he has done all his concour classics this way incl the E Type) and it still looks like new, goes on thick so fills the air holes and looks very smooth.

I got away with the starter ring in the oven and flywheel in the freezer a few years ago, but the wife was out handbag shopping! again! She's just got a new iphone it's bigger than the old one & won't fit in the pockets of her numerous handbags SOO off we go again, more handbags! & she ain't cheap their designer labels, fortunately were still in lockdown so non essential shops shut, Ha! But it makes my eye's water when I think of all the Triumph goodies I could get!

[PeteH]

OMG!!. Handbags!. Mrs H, has serious arthritis, so hers are (have to be) "reasonable" sized. However, granddaughter, left hers on the floor, so Gramp`s picks it up before someone trip`s over it!. Damn thing weigh`s a tonne. What DO they find to put in them, Felt like 1/2 a dozen house bricks!!🤣. I reckon they will all finish up with arthritic shoulders?.

Flywheel in the freezer, SWMBO` opens chest freezer and ejects said item just a I appear from the house juggling the (very) hot ring I have retrieved from  the oven, "interesting conversation" follows!. (that was 1970`s, marriage has survived)

Pete