Removing 90+ Year Old Mud...

[staples57]

I recently picked up about a dozen relic Mills No.5 base plugs. Other than having a very brief cleaning, all the base plugs are in "as found" condition. Suprisingly, the threads are in great shape as are the base plugs themselves.
The only down side (and probably the reason why they were so cheap) is that they are all filled with 90+ year old mud.

Thinking that a little warm water, a pick, a tooth brush and elbow grease was all that was needed to clean them up was a mistake.
The mud is hard as concrete!

I don't want to take the dreaded dremel to them and risk removing any maker's marks that may still be there. Not to mention destroy the patina and completely ruin them in the process.

Any suggestions on how to remove the concrete like mud?

Cheers,
Brad

 

[dano1917]

muratic acid

Brad, I find the best for cleaning mud and looser rust is muratic acid mixed 50/50 with water. An overnight soaking and light tooth brushing should fit the bill..Dano

 

[gothica7]

I have found Spirit of Salts diluted 50/50 with water does the job just fine. Gets rid of all the rock hard mud and any gren remains.

Andy

 

[Millsman]

Andy

I use 25% Hydrochloric acid. The organic stuff disappears in seconds. Brass come up well too. Then a quick rub with brasso.

John

 

[gijunkman]

How about mounting them to a board, and taking them to the local self service car wash. The high pressure water should blast the mud right out. :tinysmile_twink_t2:

 

[Hallams]

Hello Brad,
Not so much mud, more like concrete. It and I are old enemies! I use the stuff which you can buy from builders' merchants to remove concrete splashes. After it has done it's job, I follow on with rust removal.
Regards, Dave.

 

[staples57]

Thanks for all the suggestions!
I'll give a few of them a go and get back to you with the results.

Cheers,
Brad

 

[staples57]

Thanks for all the suggestions.

Spirit of salts (aka Hydrochloric, acid muriatic acid) did the trick!

I also found that a mixture of white vinegar & salt is equally as good.
...approx 4-5 tablespoons of salt (ordinary table salt) to two cups of ordinary white vinegar

Many Thanks!
Brad

 

[gothica7]

Looks like Dano and me were onto the same stuff, no idea it was also called muriatic acid also. Dont ever try sulphuric acid on brass as it really does damage the stuff and changes its colour too. Too long in the hydrochloric can also etch out the zinc in the brass making the plugs look very copper like. However a good soak in acetic acid will make them look fantastic.

I have tried all sorts of chemicals[all bought off the shelf so none too nasty] and the hydrochloric has been the best as it also sorts the rust that can stick to the plugs from the gren bodies. Dont stick any aluminium parts such as centre tubes in it as they will also corrode rather rapidly.

Andy

 

[staples57]

Thanks Andy, that's good to know.
The last thing I want to do is ruin a piece while trying to clean it.

Cheers,
Brad

Looks like Dano and me were onto the same stuff, no idea it was also called muriatic acid also. Dont ever try sulphuric acid on brass as it really does damage the stuff and changes its colour too. Too long in the hydrochloric can also etch out the zinc in the brass making the plugs look very copper like. However a good soak in acetic acid will make them look fantastic.

I have tried all sorts of chemicals[all bought off the shelf so none too nasty] and the hydrochloric has been the best as it also sorts the rust that can stick to the plugs from the gren bodies. Dont stick any aluminium parts such as centre tubes in it as they will also corrode rather rapidly.

Andy