Sandblasting a Sword?

[Jeff D]

Hi all,

Has anyone here tried sand blasting a heavily rusted sword? I have a few projects which are heavily corroded which I would like to try it on. I have in the past tried the usual iron wool, oil and time, but, I find that it doesn't get the oxide out of the pits and grooves which could be hiding markings.
I will show a trial run I made on a old rusty square. It seems to work fairly quick. I would appreciate any tips and/or advice.

Thanks Jeff

[Atlantia]

Results look similar to vinegar de-rusting.

But I guess a damn site quicker!

[kronckew]

purists would not like the removal of the patina that has taken ages to develope, and consider a piece devalued if so treated; but if you must, i'd try glass bead blasting. it's less likely to remove precious metal and is a bit more delicate and less abrasive than sharp sand. still, it's better than taking an angle grinder to it.

[Jeff D]

Thanks Kronckew,

I used 30-60 crushed glass on the square above, and I think it is too aggressive to use on a sword. I will experiment with the glass beads next. In this thread ( http://www.vikingsword.com/vb/showth...t=sandblasting ) it was suggested to use coal slag 'black beauty', wouldn't that be more aggressive than crushed glass? Has any one used it?

Atlantia, the appearance is very similar to a vinegar etch, with a flat dull grey appearance to the metal. I think that is more a result on the oxidation below the original rust in this case? You are also right that the result took only a few seconds and is actually more controllable than a vinegar etch.

Thanks
Jeff

[G. McCormack]

maybe you could try a lighter medium, like walnut shells?

[kronckew]

having read the post no. 4, i was about to also suggest ground up walnut shells, the cutter i served on had two Solar 1000 HP gas turbine engines (as well as two 1500 HP diesels), and we would occasionally have to clean the crud off the blades, we'd slowly dump a sack of ground walnut shells in the air intake. worked a treat. nice smoke and sparks out the stern exhausts too!

other forms of shells were tried, but walnut worked the best and was the least destructive.


glass bead blasting, a less intensive form of shot blasting, can also increase the surface hardness of the metal slightly due to the compression of the metal in the teeny dimples created by the impact, where sharp abrasives are more likely to cut away material.

you can also get plastic beads for even more benign bead blasting crud removal. linky on available mtls.

[Jeff D]

Thanks guys I will give it a try.

Jeff

[Jeff Pringle]

Archaeologists use the technique, here is a Swedish article that cites the use of a microblaster with aluminum oxide abrasive to clean up & reveal details on a couple swords:
http://fornvannen.se/pdf/1980talet/1981_016.pdf
You can find very fine abrasives on line, I once got some 40μ glass beads from a company that supplies equipment for cleaning up dental castings.

Gunnel Werner
“Konservering av tre vikingatida svärd med inläggningar”
“Med hjälp av mikrobläster (aluminiumoxid som blästermedd) frilades de fragmentariska inläggningarna av tunna koppar- och bronstrådar på hjälten och knappen.”

[Ferguson]

Jeff, I use a mild chemical called Evapo-Rust. Don't know if it's available in B.C. though.
http://www.evaporust.com/evaporust.html
It will, with soaking, remove serious rust. But it's not a harsh chemical like Naval Jelly. It does remove all the patina though. I buy mine at Pep Boys auto parts store.

Steve

p.s.
Here are the distributors in B.C. if you're interested
http://www.nicks.ca/ER.dist.html

[ward]

Sandblasting antiques is a bad idea. It ruins the value of a piece giving it a pebbled finish that can not be repaired. Also the dead gray appearance is disturbing. I would strongly suggest using milder options. Leaving patina in crevaces is what gives a piece some character not a factory overcleaned appearence.

[Jeff D]

Thank-you Jeff, Steve and Ward for your replies.

I was able to get the glass beads (not sure of the size) and walnut shells yesterday, and will try to get the Evapor-Rust (by Steve's link there is a local distributor). Time to bring out the rusty square again and do a side-by-side comparison of the different methods.
My concerns are as exactly stated by ward, I do not want a dull over cleaned result, but, the problem is I really don't like the rusted appearance either. I suspect the rust is also hiding marks and information as well. I will accept the rust over destroying the piece however.
It may take me a week or two try all the methods and I will post the result when I am done.

Thanks again everybody!
Jeff

[ausjulius]

please do not sand blast any antique or for that matter new cutlery,, it will damage the finish and only premotes rust, unless your making tactical finished military style knives sand blasting has no place...