Rust Removal with Tomato Paste

t_c · 17th April 2008, 06:55 AM

Thought I'd share this little experiment with you...

I have had a very hard time trying to clean up some nasty deep black pits in this blade (sanding, scrubbing, WD40, etc). I didn't want to use an immersion technique (pineapple juice soak or similar) because I'm not sure how to get the handle off and the rust is only really bad in certain areas. I decided to try tomato paste, the advantage being that I could apply it to just the areas I wanted to and not have to treat the whole blade. The areas of the blade that aren't black and pitted are in pretty good shape. I applied about 1/4" thick coat of tomato paste and let it sit for about 3+ hours - I tried a 1/2 hour and 1 hour, but it didn't do much. Most of the tomato paste dried and turned almost lack after 3 hours. I cleaned the paste off with a brillo pad, sanded, and REALLY scrubbed with a brass wire brush, and a lot of rust came away. The tomato paste does etch the blade, but I was able to sand it clean. I did two coats (3 & 5 hours +-) and got some decent results. One side is mostly done, the other is untreated - sorry no real before and after pics, but both sides were in the same condition originally. The pitting is visible, but the heavy rust is gone.

I want to take the handle off to clean the tang and stablilize the wood as the rust on the tang (I'm assuming it's the rust) has expanded to the point of splitting the wood handle. The handle is on really well though. Does anyone have any tips on removing the handle safely?

thanks
tom

A. G. Maisey · 17th April 2008, 07:37 AM

That's good lateral thinking, TC.

Tomatoes = acid, tomato paste = acid paste. Good!!

I have removed a great many rusted on, glued on---with both western glues and native glues---handles, and I have never yet come across one that would not move with the application of heat.

Heat the area of the blade for a few inches below the handle, a candle or a small kerosene lamp is safe, but if you can control the heat, a propane torch is quicker and cleaner. Hold the blade with your bare hand a few inches below where you are heating. When it gets too hot for your hand, back off the heat until it cools a bit. Firmly moving the handle back and forth, up and down, will eventually loosen even the most resistant handle. If you cannot free it up with just one try, put it away, let it cool completely, and try again tomorrow. It will eventually loosen up enough to come free.

kahnjar1 · 17th April 2008, 08:56 AM

I still believe that Pineapple juice is by far the best means for NON DESTRUCTIVE rust removal. You do not have to remove the handle. Make yourself a suitably sized "bath" out of a piece of plastic pipe with 1 end capped. Suspend sword/knife in juice by using a wire bent to suit. See pics herewith. All you need for serious rust is PATIENCE, and plenty of it. Take blade out every so often and rub it with SCOTCHBRITE> no scratching and in fact it will polish eventually.
GOOD LUCK!!

A. G. Maisey · 17th April 2008, 11:29 AM

Yeah, you're right, pineapple juice is the ducks guts.

I've been recommending it anybody who will listen for about 50 years.

In fact, if I was doing this blade, I'd demount it first, then juice it.

However, TC didn't know how to get the blade off. Personally I think that tomato paste option is pretty smart thinking. OK, its got limited use, but I really do like the idea, and I intend to try it when something suitable falls into my hands.

t_c · 18th April 2008, 03:42 AM

I agree with both of you on using pineapple juice, I have used it on a keris, and it does work really well. I don't have a proper shop right now, so making the PVC tube would entail making a stand for it to hold it upright (I've been working out of my bathroom), but I like the idea. The tomato paste really does have limited uses, and it wasn't my first choice either, but it came in handy in this specific instance.

I'll try using the heat method to remove the handle - I always hesitate to take heat to a tempered blade, but I understand from your description not to overdue it.

thanks, tom

A. G. Maisey · 18th April 2008, 05:00 AM

Heat doesn't hurt a heat treated blade as long as you keep it within the range the blade was drawn to originally. Bearing in mind these low tech blades were probably made from something like spring steel and drawn to a blue, as long as you're within that heat range, you're not doing any harm. There's another thing too:- a lot of these sort of blades were not hardened and drawn all the way up to the tang. If you etch the blade you can see where the hardening has occurred, and more often than not its along the edge, and tapers off completely before it gets up to what would be the ricasso area. In practical use terms, this makes a lot of sense.

An easy stand for an upright soaking container is a box of sand---cardboard box, put some sand into it, or even earth if you don't have sand, and sit the pipe upright in the sand.

Dmitry · 9th July 2009, 05:14 PM

Does the pineapple juice etch the blades, being acidic in its composition?

kahnjar1 · 10th July 2009, 08:10 AM

Quote:

Originally Posted by Dmitry

Does the pineapple juice etch the blades, being acidic in its composition?

VERY slightly but is easily polished off.
Regards Stuart

M ELEY · 11th July 2009, 02:39 AM

I recently cleaned an old Queen Ann cannon barrel flintlock with the ol' pineapple juice and it worked very well, getting rid of the dull luster without completely removing the old patina. I've used pineapple juice likewise on keris, but because the gun had its grip and I didn't remove the keris hilt, I used tissue paper soaked in the juice to act as a kind of acid paper machet' (spelling!). This is a little messy, but if applied right, works the positive effects of acid etching while allowing cleaning in specific areas. I even wrapped the soaked tissue around the trigger guard without having to involve the trigger itself (which was of another metal and didn't need it). Anyway, my two cents...

17th April 2008, 06:55 AM	#1
t_c Member Join Date: Jun 2006 Location: ca, usa Posts: 92	Rust Removal with Tomato Paste Thought I'd share this little experiment with you... I have had a very hard time trying to clean up some nasty deep black pits in this blade (sanding, scrubbing, WD40, etc). I didn't want to use an immersion technique (pineapple juice soak or similar) because I'm not sure how to get the handle off and the rust is only really bad in certain areas. I decided to try tomato paste, the advantage being that I could apply it to just the areas I wanted to and not have to treat the whole blade. The areas of the blade that aren't black and pitted are in pretty good shape. I applied about 1/4" thick coat of tomato paste and let it sit for about 3+ hours - I tried a 1/2 hour and 1 hour, but it didn't do much. Most of the tomato paste dried and turned almost lack after 3 hours. I cleaned the paste off with a brillo pad, sanded, and REALLY scrubbed with a brass wire brush, and a lot of rust came away. The tomato paste does etch the blade, but I was able to sand it clean. I did two coats (3 & 5 hours +-) and got some decent results. One side is mostly done, the other is untreated - sorry no real before and after pics, but both sides were in the same condition originally. The pitting is visible, but the heavy rust is gone. I want to take the handle off to clean the tang and stablilize the wood as the rust on the tang (I'm assuming it's the rust) has expanded to the point of splitting the wood handle. The handle is on really well though. Does anyone have any tips on removing the handle safely? thanks tom Attached Images

17th April 2008, 08:56 AM	#3
kahnjar1 Member Join Date: Aug 2007 Location: CHRISTCHURCH NEW ZEALAND Posts: 2,739	PINEAPPLE JUICE!!! I still believe that Pineapple juice is by far the best means for NON DESTRUCTIVE rust removal. You do not have to remove the handle. Make yourself a suitably sized "bath" out of a piece of plastic pipe with 1 end capped. Suspend sword/knife in juice by using a wire bent to suit. See pics herewith. All you need for serious rust is PATIENCE, and plenty of it. Take blade out every so often and rub it with SCOTCHBRITE> no scratching and in fact it will polish eventually. GOOD LUCK!! Attached Images

17th April 2008, 07:37 AM	#2
A. G. Maisey Member Join Date: May 2006 Posts: 6,890	That's good lateral thinking, TC. Tomatoes = acid, tomato paste = acid paste. Good!! I have removed a great many rusted on, glued on---with both western glues and native glues---handles, and I have never yet come across one that would not move with the application of heat. Heat the area of the blade for a few inches below the handle, a candle or a small kerosene lamp is safe, but if you can control the heat, a propane torch is quicker and cleaner. Hold the blade with your bare hand a few inches below where you are heating. When it gets too hot for your hand, back off the heat until it cools a bit. Firmly moving the handle back and forth, up and down, will eventually loosen even the most resistant handle. If you cannot free it up with just one try, put it away, let it cool completely, and try again tomorrow. It will eventually loosen up enough to come free.

17th April 2008, 11:29 AM	#4
A. G. Maisey Member Join Date: May 2006 Posts: 6,890	Yeah, you're right, pineapple juice is the ducks guts. I've been recommending it anybody who will listen for about 50 years. In fact, if I was doing this blade, I'd demount it first, then juice it. However, TC didn't know how to get the blade off. Personally I think that tomato paste option is pretty smart thinking. OK, its got limited use, but I really do like the idea, and I intend to try it when something suitable falls into my hands.

18th April 2008, 03:42 AM	#5
t_c Member Join Date: Jun 2006 Location: ca, usa Posts: 92	I agree with both of you on using pineapple juice, I have used it on a keris, and it does work really well. I don't have a proper shop right now, so making the PVC tube would entail making a stand for it to hold it upright (I've been working out of my bathroom), but I like the idea. The tomato paste really does have limited uses, and it wasn't my first choice either, but it came in handy in this specific instance. I'll try using the heat method to remove the handle - I always hesitate to take heat to a tempered blade, but I understand from your description not to overdue it. thanks, tom

18th April 2008, 05:00 AM	#6
A. G. Maisey Member Join Date: May 2006 Posts: 6,890	Heat doesn't hurt a heat treated blade as long as you keep it within the range the blade was drawn to originally. Bearing in mind these low tech blades were probably made from something like spring steel and drawn to a blue, as long as you're within that heat range, you're not doing any harm. There's another thing too:- a lot of these sort of blades were not hardened and drawn all the way up to the tang. If you etch the blade you can see where the hardening has occurred, and more often than not its along the edge, and tapers off completely before it gets up to what would be the ricasso area. In practical use terms, this makes a lot of sense. An easy stand for an upright soaking container is a box of sand---cardboard box, put some sand into it, or even earth if you don't have sand, and sit the pipe upright in the sand.

9th July 2009, 05:14 PM	#7
Dmitry Member Join Date: Jul 2009 Posts: 607	Does the pineapple juice etch the blades, being acidic in its composition?

11th July 2009, 02:39 AM	#9
M ELEY Member Join Date: Dec 2004 Location: NC, U.S.A. Posts: 2,094	I recently cleaned an old Queen Ann cannon barrel flintlock with the ol' pineapple juice and it worked very well, getting rid of the dull luster without completely removing the old patina. I've used pineapple juice likewise on keris, but because the gun had its grip and I didn't remove the keris hilt, I used tissue paper soaked in the juice to act as a kind of acid paper machet' (spelling!). This is a little messy, but if applied right, works the positive effects of acid etching while allowing cleaning in specific areas. I even wrapped the soaked tissue around the trigger guard without having to involve the trigger itself (which was of another metal and didn't need it). Anyway, my two cents...