gunscrews

[Jerry V Lape]

Do I really need to buy unplated screws from one of the supply houses for the buttplate and other applications or can I strip the plating off those at the local hardware store by sanding or grinding and achieve the same end?

[tallbear]

Jerry
The plating can be removed by dumping the screws in Muriatic acid for a couple of minutes.Just do it out side.I do a whole box at a time.

Mitch

[Ky-Flinter]

Same thing can be done with most toilet bowl cleaners.

-Ron

[Chris Evrard]

I use muratic acid too. Sulfuric or battery acid works as well. But as tallbear said only outside, and even then make sure they are downwind of you. It will make a green gas when the acid goes to work. Usually 5 minutes or so and all the zinc is gone.

[mjm46@bellsouth.net]

Other than removing the plating what does the acid do to the surface of the screws? Do they get rough?

[T*O*F]

can I strip the plating off those at the local hardware store by sanding or grinding and achieve the same end?

The problem today isn't so much about stripping the galvanizing off, but rather finding a store that carries screws that don't have Phillips heads on them.  The trend seems to be replacing slotted screws with them as they restock their shelves.

For what it's worth, Tennessee Valley Manufacturing sells unplated screws in bags of 50 for less than you'd pay at a hardware store.

[Chris Evrard]

Other than removing the plating what does the acid do to the surface of the screws? Do they get rough?

Yes it does rough the up a bit. In fact if you don't rinse them off well they will brown up quite nicely on their own

[D. Taylor Sapergia]

I buy my gun screws from this site.  Excellent quality, and inexpensive, even with the shipping to the Great White North.


http://www.blacksmithbolt.com/gpage9.html

[davec2]

Dip the screws for 10 to 20 SECONDS in full strength pool acid (muriatic  - correctly called hydrochloric acid), rinse in clear water and then neutralize by dipping in a little water mixed with baking soda.  Rinse in clear water once more and dry.  The "green gas" that comes off is just hydrogen but it does have some vaporized acid in it as well.  By dipping for just enough time to take off the flash plating of zinc, the surface finish will not be roughened at all.

[Kevin Houlihan]

Does the muriatic acid work to take off the black oxide coating also?

[gusd]

What Taylor said!!
All types of unplated scrs.
Gus

[Artificer]

Does the muriatic acid work to take off the black oxide coating also?

Yes it does, IF you stick to the time limits and neutralizing methods Dave C mentioned.  Just PLEASE be careful of one thing!!  That is - IF you don't leave them in quite long enough and after you dip them in the water you find not quite enough finish is off them, DON'T plunge them right back in the acid with the water still on them!!!!!  Even though small, it will cause a somewhat violent reaction that can spit acid back at you.  So air dry or blow dry the parts first.  When we did that work, we had chemical resistant gauntlets, special heavy jacket and face shields on. 

We used to dip Stainless Steel National Match Barrels in straight Muriatic Acid  that were mounted on our M40A1 Snipers Rifle Actions using basically the same method.  It was necessary to do that to "strike" the surface so special Black Oxide Salts for SS would "stick" to the barrels correctly.  It did NO harm whatsoever to those super quality barrels, or we would not have done it.
Gus

[Bob Roller]

Somewhere in my shop are some small bottles that medicine came in that have a bunch of VERY small screws.
If anyone wants them or can actually use them,postage will get them.They were given to me years ago by a man who is still a good friend.

Bob Roller

[Bob Roller]

The OLD warning was,Acid into water but NEVER water into acid.
I saw a demonstration of that,deliberately done just to show how
potent sulphuric acid is when invaded by a few drops of water.
Some drain cleaners use or did use sulphuric acid and one man here
lost both eyes to water being poured in on top of the drain cleaner.
BE CAREFUL with these potent corrosives because forgiveness isn't in their mix.

Bob Roller

[Jim Kibler]

Personally, I've been disappointed with all the screws I've bought recently.  The slots range from big to absolutely huge and the overall quality is pretty poor.  I'm not looking for a paper thin slot, but just something reasonable.  I hate having to go through the process of pounding them in a countersunk plate and reshaping / re-cutting the slots.  So, if anyone has a GOOD source let me know.  I've had a few recommendations in the past and I wasn't too happy with what they had to offer.  As an aside,  I acquired an old beat up wardrobe cabinet from maybe 1900 or so a while ago.  The screws holding the hinges on were beautiful.  Exactly what a person would want.  I swapped them out with new ones and use the old ones on a patchbox I was working on.  

[shortbarrel]

I gave up years ago, trying to find good wood screws, like the old screws. I make my own screws on a lathe or with tools I made years ago, screw grinders and threading plates. This doesn't help the fellow who started this post one bit, but someone with a good screw machine could sure help out the gun builders. Anyone got a good screw machine wanting to make a few bucks

[Elnathan]

Cider vinegar will strip zinc from steel, and is difficult to hurt oneself with.

[eddillon]

These screws are expensive but really fill the bill because the extra high heads can be filed to the desired height.  Screw can be used during your build over and over.  When you are ready for the final fit, mark along the side of head the desired direction of the new slot.  File the head and cut the slot.

http://www.csmcspecials.com/category_s/13.htm

[Jim Kibler]

These screws are expensive but really fill the bill because the extra high heads can be filed to the desired height.  Screw can be used during your build over and over.  When you are ready for the final fit, mark along the side of head the desired direction of the new slot.  File the head and cut the slot.

http://www.csmcspecials.com/category_s/13.htm

Those are some nice looking screws, but they are some odd shapes and sizes.  There only seems to be a couple with coutersunk heads and they seem to be odd angles.  These may work okay for butplates but I don't see any that would work for boxes etc without chamfering the heads so they will fit a countersunk hole.  I may get a few to see how they work, though.

[Curtis]

Somewhere in my shop are some small bottles that medicine came in that have a bunch of VERY small screws.
If anyone wants them or can actually use them,postage will get them.They were given to me years ago by a man who is still a good friend.

Bob Roller

Bob, I would be interested in those screws!  That is a generous offer.

Curtis

[Bob Roller]

Curtis,
I use USPS priority mail which is $5.80.
These screws appear to be new flathead
counter sink type.Mostly steel and maybe
a few brass.They are not new manufacture,
only new old stock.There are also some
VERY tiny nails that I can't figure out the
use for and they will be in the box as well
My snail mail is:
Bob Roller
1805 Monroe Ave
Huntington,WV
   25704

[Jerry V Lape]

I finally found some on Brownell's website.  A dozen #10 screws (I only need 2 or 3) for $5.99.  The website wanted an additional $8 for shipping!  Talked to their customer service dept and they came up with a reasonable shipping fee.  Good company but to remain such they certainly maintain a healthy profit margin.  I know a couple of old hardware stores which has old stock from the early 1900s.  I will make a point of scouring their stock for such items.  Found some old stock files there last year - Nicholson made in USA.  And an old Case pocket knife.  The one store was opened in 1880s by the current owners grandma and he continues to stock much of the same material she did when he can find it.

[Long John]

For the record, any greenish colored vapor or gas evolved from a reaction involving hydrochloric (muriatic) acid is NOT hydrogen.  Hydrogen is both colorless and non-toxic in low concentrations.  The green or yellow gas is most likely hydrochloric acid, its appearance changes with concentration and humidity and it is quite toxic even in low concentrations.

Almost any acid will dissolve the zinc plating off of steel screws.  The stronger the acid the faster the reaction.  Yes, lowly vinegar will work but it takes a while.  Your nitric acid also will work but do NOT use the resulting solution for stock stain!  When you use an acid to dissolve a plating metal like zinc the reaction generates heat which vaporizes some of the acid solution.  Most mineral acids are toxic.  Be careful!

Best Regards,

John Cholin

[Jerry V Lape]

Long John,  Where did the chlorine from the HCL go if not in the gas.  That is what would concern me. 

[jerrywh]

Long John,  Where did the chlorine from the HCL go if not in the gas.  That is what would concern me. 

  Dave Crisali is a scientist. I would not care to argue with him over tech matters. He has help me figure out some very complicated problems.