Frozen screw...

I've got a Sht LE Mk I *** (Sparkbrook 1905) that I've been searching for parts since I acquired it in 2008. Well, finally, someone is making forestocks for the old girl, and I'm moving forward. Yes, a moron tried to make her into a deer rifle... :nono:

I've got a dial sight pointer with screw and spring, and I want to transfer the base to the new stock. The problem is, the screw is frozen. :banghead: I've tried "Kroil" to no avail. I thought about destroying what's left of the forestock to remove the entire sight base and use heat to remove it. Any thoughts? Thanks in advance.

How long have you been kroiling it? Patience and some gentle heat will help. Removing the spanner screw that holds the pointer and spring washer will let you apply the kroil directly to the fixing screw and also keep the heat from ruining the spring washer.

Quote:

---

Originally Posted by WillSarchet

How long have you been kroiling it? Patience and some gentle heat will help. Removing the spanner screw that holds the pointer and spring washer will let you apply the kroil directly to the fixing screw and also keep the heat from ruining the spring washer.

---

Thanks for the reply. I've been adding Kroil for almost two weeks. The sight has been stripped. To add insult to injury, the stock was filed or sanded down taking almost half of the screw head with it.

I was taught that for a seized screw or bolt the correct amount of heat to apply is so that the it is just marginally too hot to touch.

Heating with a soldering iron works.

I'd like to see some photos of exactly what we are talking about here. It may help work out the best way to deal with this screw.

That would be a serious "plumbing-grade " soldering iron; not something you would use on printed-circuit boards.

Use an automatic centre punch on it, hit it face on off to the side till you get a nice dimple. Has to be an automatic one, the jolt from firing cannot be matched with a hammer and punch.

Then strike it round with a hammer. Also use a soldering iron, stick the tip of the iron in the dimple. And yes a standard PCB grade soldering iron is fine, i used a Weller Pyropen.

I removed a grip screw from a 100 year old Luger where the head was rusted solid and the slot was stripped using that technique. Be persistent but patient, walk away and come back.

Quote:

---

Originally Posted by Bruce_in_Oz

serious "plumbing-grade " soldering iron; not something you would use on printed-circuit boards.

---

I remember back in the 1980's someone using a "serious plumbing grade soldering iron" to "build" himself one of those self assembly computer kits that use to be on the market. I'm not sure that he ever got the thing to work, despite the hours of fiddling. It was like the most enormous soldering iron that I had ever seen in my life but why the chap thought it a good idea for electronics I've no idea.

It's all about using the right tools for the right job.

My reason for suggesting the "big iron", is that part of the trick is to get as much heat into the metal bits before it starts to "migrate" outwards. And I have one in "the Dungeon'. Is that the gas-fired "Pyropen" that sounds like a small jet engine as it starts up?

Yes the Pyropen is gas fired, cool little tool. It has the power to get the heat in quick enough if you ramp the power up!

It does sound like a small jet engine and with a quick nozzle change is also a blow torch!

Quote:

---

Originally Posted by 30Three

I'd like to see some photos of exactly what we are talking about here. It may help work out the best way to deal with this screw.

---

Here's the culprit.

I'd get out my impact driver...

If it's really that tight I'd consider whether it was absolutely essential to remove it in the first place. However, if so, it might be worth making a rudimentary tool akin to the striker disassembly tool to grip the two semi-circular recesses either side of the threaded stem on the volley sight range plate. This will at least help to stop it twisting & potentially ripping the woodwork if it does move if you really have to give the screw some serious wellie.

Before doing that, as you've been advised above, a little local heat (obviously with care because of the proximity of the wood), combined with a little clutch/steering system fluid. I was recommended this years ago as a better alternative to most commercially available penetrating oils. Even so, you need to be patient, putting on several applications, & leaving it for a couple of days to soak in. It has worked well for me in getting many rusted in screws in SMLE's, & also the tiny 8 BA screws in rusted up No32's. It's also cheap & readily available as you can use old discarded stuff - it doesn't need to be new.

I'm not concerned with the stock. It's been cut down and sanded to the point of being useless except as a source of patch material. A set of reproduction handguards overhang the stock by 1/8". Here's an overall shot of the rifle as I purchased it. Luckily, the barrel wasn't cut down. I still cannot understand why someone would take a rare rifle and cut it down. Whatever the reason, they took a rifle worth maybe $1,000, at the time, and turned it into $100.

If the stock is truly scrap then you could always cut round the plate & screw removing them from the wood completely. You'd then be able to get at the screw threads much better. The penetrating oil & heat would go straight to where they are needed. It might sound drastic, but if that forend is just firewood.....

In fact, you could hold the screw shank in a small vise & try rotating the plate to unscrew it (after a good soaking with a penetrant).

Is there any chance of finding a replacement screw? Seeing as these have been sanded and damaged. If so I'd just drill the head of the rear side and punch out the screw.
If you are scraping the wood, then do as Roger says; destroy the wood to save the part.

Quote:

---

Originally Posted by 30Three

Is there any chance of finding a replacement screw? Seeing as these have been sanded and damaged. If so I'd just drill the head of the rear side and punch out the screw.
If you are scraping the wood, then do as Roger says; destroy the wood to save the part.

---

I haven't seen one yet. The other alternative is to have one made. If I had a tap and die, I could make one myself. But, I understand that the threads are proprietary.

If the info in Stratton is correct, then an 8-36 thread, possibly thinned down a few 1/1000", ought to be close enough to be eased in. My experience is that ordinary steel screws can often be reformed a touch by the (usually) much harder gun parts into which they have to be fitted.

(Later)
I think the dimensions in Stratton are rounded up. The (no longer available) Enfield Apprentices site had a table that showed 0.1656" x 37 tpi.
8-36 is 0.164" x 36 tpi. So no need to thin the thread, just grease it well and use the method "In until it sticks, then screw it out. In a little further, then out again..." etc. and it should be reformed by the dial sight thread, especially as the length of thread is quite short.

The most important piece of equipment here is your patience!

P.S: Have you tried the counter-intuitive method of first trying to TIGHTEN the screw as hard as you dare!
This can sometimes break the bond that is causing the screw to stick.

100% would come out with automatic centre punch!!

The thread on that screw is: .1656dia x 37tpi.

A classic "Enfield Special".

Not something they stock at the corner hardware shop; ditto the taps and dies.

And think of all the fun you can have shuffling the extra gears for your lathe gearbox to set it up for 37 TPI. Bear in mind that 37 TPI has a pitch of 0.686486486486mm, which is VERY close to 0.7mm. You can easily do that on a metric lathe. (M4 has a pitch of 0.7mm). Interestingly, the nominal diameter works out to 4.20624mm. Hmmmmm....

However, if you have a tame CNC shop nearby, and the like a challenge, you have the technology. The operator simply plugs in a CORRECTLY ground thread-form tool (NOT 60 degree), "tells' the machine what pitch and diameter are required at the correct stage and the machine does its thing. Think: infinitely variable ratio drives. Unless your friendly CNC shop is VERY tame, one screw will cost an arm and a leg. However, a hundred is just a couple of key-strokes away and wildly cheaper per unit. Keep a few for future projects and offer the rest for a reasonably sane price on the "for-sale" pages here. A win for everybody.

I've been down that track getting screws and other dinky bits made for the Francotte-actioned BSA Martini Cadet rifles. Still steadily selling off the "extras", which, in turn, has put me in contact with some interesting folk and THEIR projects / problems.

By the way, the P-14 dial-sight retaining screw has EXACTLY the same thread. Not too sure about overall length; someone out there will know to the last micron.

Cheers!

That's not the right thread. The Screw, Sight, Dial, Fixing uses a 0.181"x26 1/3 tpi Enfield thread. Using a gear calculator I was able to figure what will give me 26.347 tpi, which should be close enough, I just haven't gotten to making any yet as I don't need them right now and I do have plenty of other lathework on the table.

My recollection was that the bezel holding the pointer was a smaller thread to the thru bolt, basically a stepped hole.

The tatty example was in a scrap forend & you can see how rusted in the screw was. It is still in, but when the day comes that I really need that specific plate badly enough I'll get it out. If the plate assembly is removed from the scrap woodwork there is a significant area of screw shank to hold in a vise. If you first give it a little wellie with a heat source a few times, the heating & cooling of it will rupture the bonds holding the rust. Then leave to soak in penetrant. Finally, using your hand, unscrew the plate from the screw (screw held tightly in vise).

It will come out, & you won't have to damage the screw to do it.

If you have the facilities to make a replica screw, that looks as it should externally. Would it no be easier to use a modern thread. It would make life easier and the thread is not visible when fitted.
So would it be a problem?

Quote:

---

Originally Posted by 30Three

If you have the facilities to make a replica screw, that looks as it should externally. Would it no be easier to use a modern thread. It would make life easier and the thread is not visible when fitted.
So would it be a problem?

---

Only if you're also making a replica plate. Thread has to match the thread in the plate for it to work properly.

If the original screw approximates to say, 3 BA, just make the replacement to that size & run a 3 BA tap down the thread inside the plate. Bob's your auntie!

The question is whether you think it is stuck in the wood or the metal of the sight dial?

I would suspect the screw is well and truly rusted into the wood of the forened. Anyone who has seen old wooden objects that have rotted to the point of falling apart may have seen how fragments of the wood fibres remain bonded to the screw threads even after all the softer surrounding wood has rotted away. That's what you're up against.

A small hex impact driver might be useful, if there is enough of the screw slot left to use one. Something like this perhaps.

If the forend is indeed scrap why not just remove the whole of the volley sight plate & screw assembly from the wood? You can get at the metalwork then. The volley plate screw is cheese headed, incidentally. The threads are likely rusted into the volley plate though there may well also be some adherence of the corroded shank of the screw in the wood.

Even if the forend is damaged further by the removal of the metal, it still has uses. I use such scrap pieces of woodwork as 'donors' for patches needed on otherwise serviceable woodwork. For example, the raised & rather thin piece of wood that often breaks off, located at the right rear of the forend between the charger guide recess & the very back end, can be carefully salvaged & grafted onto a needy piece of wood (glued & dowelled/brass wired)........pieces can be cut out of the area of the trigger guard recess & grafted on to another piece so as to make it usable again......& so on. Waste not want not!

Quote:

---

Originally Posted by Roger Payne

If the forend is indeed scrap why not just remove the whole of the volley sight plate & screw assembly from the wood? You can get at the metalwork then. The volley plate screw is cheese headed, incidentally. The threads are likely rusted into the volley plate though there may well also be some adherence of the corroded shank of the screw in the wood.

Even if the forend is damaged further by the removal of the metal, it still has uses. I use such scrap pieces of woodwork as 'donors' for patches needed on otherwise serviceable woodwork. For example, the raised & rather thin piece of wood that often breaks off, located at the right rear of the forend between the charger guide recess & the very back end, can be carefully salvaged & grafted onto a needy piece of wood (glued & dowelled/brass wired)........pieces can be cut out of the area of the trigger guard recess & grafted on to another piece so as to make it usable again......& so on. Waste not want not!

---

That's exactly my plan, Roger.

I just thought of this. I snapped off two bolt heads changing a thermostat on a car. I heated the stubs to red, sprayed them with WD-40, and aftercooling backed the bolts out with no problem. I thought I'd do something similar with this.

A point to bring up, what was the original finish on the plate, in case I have to refinish it?

Rust blued, but smaller component parts when they were refurbished were often oil blacked.

You shouldnt need to heat this to red, you risk causing too much damage to other components.

Have you actually tried any of the suggestions?

I recall the "blacking" technique was called "blazing off" and involved heating the component (but NOT to a sparkling red heat), briefly dunking it in "oil" (probably whale oil in the "good-old days") and then letting the remaining heat IGNITE the oil on the component. This was done to small components that could not sensibly be "slow-rust" "Blued / Browned", etc. (Imagine the fun to be had rusting and manually carding-off all those tiny pins, screws and "knickknacks" in a SMLE It was NOT applied to larger components nor, especially those that had been heat-treated to a specific hardness. Bolt bodies were partially "blacked". I've seen the "finish requirements and specs thereof "somewhere".

Also, Lithgow was playing around with "Parkerizing" before WW2 as it was seen as a more consistent finish for several components, including the body and the magazine. It appears that they were using a "Zinc' based brew as there were concern of the finish "not being black enough" for service acceptance. Manganese-based Parkerizing is distinctly darker in colour.

Once more, into the dungeon!

There is a VERY good reason most modern commercial gun-makers use HOT blue systems like DuLite, for example. It might not look as spectacular as a bespoke slow-rust job, but you don't have to have unlimited funds to buy the finishd product, either.

I had a few moments spare whilst working in the garage earlier & decided to see how long it would take to get the heavily corroded screw out of the volley sight range plate. The whole procedure took less than ten minutes, much of which was waiting for the assembly to cool enough to handle with my fingers after I'd heated it.

Firstly; clean off any loose rust with a wire brush before heating the screw - you can use rather more than you could if it was still in the woodwork, but not enough that it would affect heat treatment on a nice example (the screw is obviously scrap on this one anyway).
Secondly; douse in cold water to fracture the rust bonds between the screw & range plate threads.
Thirdly; gently warm to evaporate water, & then dip in penetrant (brake fluid in my case).
Ideally I'd leave it in penetrant for 24 hours or so, but I only had a few minutes, so that's all it got!
Fourthly: hold screw firmly in vice (vise in North America), & wind off the range plate using hand power, or a small set of grips if necessary (with the grip jaws padded to avoid damage to the range plate edges).

Give it a try. I'd be very surprised if it doesn't work. If the screw does get damaged then pm me as I can probably find you a replacement.

ATB.