LumberJocks Woodworking Forum banner

Best method to restore a saw blade without damaging etching

1 reading
8.2K views 18 replies 11 participants last post by  Iban  
#1 · (Edited by Moderator)
Well the title makes it clear…
I'm afraid some chemical rust removers or abrasive methods would ruin the delicate etching that remains in the blade…
Any experiences?
 
#5 ·
+1 to Johnny7's advice. I'd go a step further though if you're trying to preserve the etch and say don't start with wet/dry paper coarser than 1000. I'd be afraid of damaging the etch even with 220.
 
#6 ·
Um……clear as mud.
Sorry if I was too forthright. As I do not master english I tend to be straight to the point with little details.

And thanks for the replies.

I am restoring some old hand and backsaws. This is new to me but it is fascinating

Image


Image


I started cleaning with hard and medium scotch brite one of them and an etching showed up.
Image


I kept rubbing and sanding. And I also used brass wire brush and it went better for the blade and worse for the etching. It started fading.
Image

Now I can barely see E T Roberts & Lee / PARKSTONE but appeared Don works Tottenham London

I think I went too much coarse but that was a test. Here we say you need to break some eggs to make an omelette for the first time

Then came sanding the handle and sharpening but that is for another thread.
 

Attachments

#8 · (Edited by Moderator)
Yes, IMO it is if you are trying to preserve the etch. However, you could use a random orbit sander and put a fine scotchbrite pad under it and use some WD-40 as lubricant. I wouldn't get any more aggressive than that if it was me and I wanted to keep the etch.

Edit to add: My original comment was assuming you've already scraped it with a razor blade as Johnny suggested. After that, there should be little sanding left to do since surface rust should be gone.
 
#9 ·
Is it more important to preserve the etch or get the saw back into peak operating condition? In my experience those are usually mutually exclusive.
 
#12 ·
Never tried evapo rust or hammerite rust remover gel (as seen in Brit's blog posts).
Hammerite is not available anywhere around here. Evaporust es quite pricey but may be worth a try.
I've seen evaporust gel but not available even in amazon US

The rust remover I have is also a gel but I doubt is adecuate… It has a very strong acid smell, like 100 times lemon juice and it leaves a white coat in the steel that disappear when scrubing and rinsing…
May be too aggresive
 
#13 ·
I guess it depends on your goal.

By "restoring" an old tool, you already lost value for collectors. So if your goal is to just make it bright and shiny, then sand with wet dry paper, i would start at 600 with 3in one oil or wd40 or whatever else you want to use as lube, then 800 and 1000.

If your goal is to jist make it work better for a user, try sand through the pitting but you can stop at 600 for a user.
 
#14 ·
Try Cold Gun Blue paste. Wipe it all around and over the etches…let it sit a while. Come back later with a very stiff sanding block, and fine grit sand paper….goal being to remove the "blue" above the etch…while leaving the blue down in the etch….

Use the paste, not the liquid blue…as the bottle stuff doesn't get very thick..and wears off rather quickly…
 
#15 ·
Started a new restoration of a Disston. After some delicate scrubing I didn´t see any signs of etching so no need to be gentle.
Image


First by hand with a scraper following by coarse scotch brite and 80 grit sandpaper.
Then I wanted to try some electric aid.
Seems like the eccentric works better than the belt sander. At least the disc does not clog as much as the belt. Also the belt sander tends to leave sanding marks.

I used wd40 and glass cleaning liquid for lubricating. Sanding by hand I didn´t see much difference but with the eccentric likes more wd40. Also de dirt mess is bigger with wd40 so it may indicate that is more efficient too?

I will continue with 220 grit and see what it comes
 

Attachments

#17 ·
Johnny7 has the right idea. You do not want the abrasive to "reach" the etch. The razor blade held like a scrapper will not dull the etch. Kenny is also correct in his choice of abrasives above 1,000 grit; use a hard block that won't flex.

Stay away from the evapo-rust.

Saving an etch is a long hard process, shortcuts will come back and bite you.
 
#18 ·
Clamp the teeth between two pieces of hardwood to protect them, then use a wire brush (preferably one on an angle grinder) to remove the loose rust, then use coarse, medium and fine emery cloth, then crocus cloth, to smooth the surfaces, then polish with emery compound.
 
#19 ·
Clamp the teeth between two pieces of hardwood to protect them, then use a wire brush (preferably one on an angle grinder) to remove the loose rust, then use coarse, medium and fine emery cloth, then crocus cloth, to smooth the surfaces, then polish with emery compound.

- HapHazzard
I´m not familiar with those. Is emery cloth Scotch brite type fleece? And crocus cloth? I´ve never heard of it here in Spain