Epoxy Scrapers

[Howard]

Lots of folks advocate scrapers over sanding of cured epoxy, at least initially to get a nice smooth finish.

I've seem some homemade tools for this job, made from saw blades...both circular and old handsaws.

My question is how to cut up a saw blade. Will a fine blade, bi-metal sabre saw blade cut it? I've got an old carbon steel plywood Craftsman blade from my radial arm saw...dull and it won't be used again....or I could probably find an old hand saw at the local antique malls....better steel than you can buy and about $2.

If you sharpen those up...about what angle would you shoot for on the edge? I'm thinking about building a simple sharpening jig using that Scary Sharp method. I'm guessing around 20 to 25 degrees.

[capt jake]

I use hand paint scrapers. The handle on them is pretty handy. I have several ground to different profiles. I also have a cabinet scraper, they are pretty cheap to just buy vs making one.

Sharpening? Nearly 90 degrees (or flat). Then you have to roll a hook on that edge. I use an old king pin and rhe teh edge of the scraper against it to roll over the 'hook' It won't appear to be much, but you don't need much on a scraper.

I also dress the paint scrapers occasionally with a file. As I stroke the file accross the edge, it will create the burr that is needed (or hook).

I know somembody else can put this in words better than I.

[Greg Luckett]

I have been snagging scrapers from Rockler, Woodcrafe, HD, etc. whenever they are on sale. My best ones are rectangular w/o handles, which are used for fine finish work. I do not have a ready source of the wide saw blades to cut up and want at least 2 inches in width if no handle.

http://www.woodcraft.com/

http://www.rockler.com/

Search on scrapers. There are lots of varieties.

It is important to dress the edges when needed.

I use this type most of all (from Woodcraft):

"Shavehooks

These beautifully made scrapers are designed for flat, convex, and concave surfaces as well as for tight corners which cabinet scrapers cannot handle - ideal for scraping paint too! The tempered steel blades, heavy shanks, and polished beechwood handles make these valuable additions to any woodworker's bench. Length - 8-3/4". UK. Honing required before use."

[Charlie Jones]

you can cut things out of old saw blades using a sharp cold chisel. Lay out the lines you want, put the metal on a backing block, line the cold chisel up on the line and whack away, moving it so you cover the entire line. It won't cut, but once you have gone along the line, the blade will break there.

Then you can layout and cut the next edge. It's much like cutting glass.

Once you get the shape you want, file the edge square, run it over a stone so it's dead square, then turn the edge with a burnisher. I have one commercially made burnisher, but an old car vavle or King pin will work well too. Anything harder than the scraper and very smooth. All surfaces need to be smooth or you'll get rough scraping.

Neanderthal Woodworker has tutorials for sharpening planes and scrapers by the way.

http://www.cs.cmu.edu/~alf/en/en.html

[Greg Luckett]

Charlie,

That Neanderthal Woodworker link led to lots of other links, which I quickly went through, but did not spot the tutorials at first glance. Never the less, it looks like a very interesting site and more time will be spent later.

Wood Magazine, a couple of years ago, had a very good article on making scrapers and doing the edges. In a fit of cleaning prior to Thanksgiving, I tossed all of those older magazines, just retaining the boating related ones, or I would be able to reference it precisely.

Thanks,

Greg.

[Greg Luckett]

Hmmm, maybe Wooden Boat or Professional Boatbuilder magazines?

[Charlie Jones]

Sorry Greg- the scraper tutorial appears to have become a dead link. Here's three other links- I KNOW they are there- I just looked at all three.

http://www.inthewoodshop.org/methods/wwc07.shtml

http://www.woodzone.com/articles/scrapers/

http://www.joewoodworker.com/scraper.htm

[Kudzu]

I've seem some homemade tools for this job' date=' made from saw blades...both circular and old handsaws.

My question is how to cut up a saw blade. Will a fine blade, bi-metal sabre saw blade cut it? I've got an old carbon steel plywood Craftsman blade from my radial arm saw...[/quote']

Never seen one made from a Circular saw blade, thats pretty thick steel, but I would suggest a dremel tool with a cutoff blade or if you happen to have have an angle grinder. I have serious doubts a jig saw is going to cut that. MAYBE a hand saw but I doubt it.

Charlie, would you method work on something as thick as a circular saw blade? I would think it would but would take a lot of extra work on a blade that thick.

[capt jake]

Power hack saw or an abrasive blade in a circular saw. Then grind off the rough edges.

[Howard]

I had assumed those scrapers I saw were just an old woodworkers homemade trick....but with your help, I see they are also commercially made and considering the price, I'll probably buy one with the sharpening kit.

There is way more to this than I knew. I thought they were just a larger version of the smaller carbide cabinet scrapers...the kind with a handle that you pull towards you. That you would sharpen them at an angle and pull them towards you. These are quit different from that. I'm looking forward to giving this a try. I've had good luck with my small cabinet scraper....much better than sanding for lots of places.

[Greg Luckett]

Howard,

I learned about scrapers on here the same way you just did. Isn't this a great forum with the best sort of folks?

Greg.

[Charlie Jones]

Kudzu- Never tried it with a circular saw blade. You're right - they are, or most of them are, pretty thick. Might be hard to do.

The problem with grinding by the way is unless you are extremely careful you over heat and lose the temper Then the piece of steel is just that- a piece of steel. The saw blades are hardened.

Guess I'll have to try it, WHEN I get moved into the new shop. Till then all I have time for is shop

[Barry Pyeatt]

One big difference is that cabinet scrapers are designed to be able to flex them. Nearly impossible with a circular saw blade made into one. My father used to make them from handsaw blades that had passed the point of no return as far as resharpening them or were broken. He took them to a local sheet metal shop and they cut them to size on a shop sheer. Did it for free for him. He would then set it in a wooden block jig that was simply two blocks of wood that had 90 degreee edges on them and clamped them together and took a good file to the edges to flatten and true them up. Then used an old valve from the scrap pile to burnihs them. He did get a little fancy and made up a nice turned handle for the valve to make it easier to handle.

I still have a half dozen or maybe more of his scrapers and they work like a charm. Good steel in the hand saw blades. Sheering them off and then filing them flat on the edge preserves the temper. If you are not careful grinding them can remove it quickly. Resharpening and putting the curl on the edge is quick and easy. More difficult to describe than do once you get the concept. And being able to flex them makes them very versitle for boat work.

I use a couple with handles as well and they are quick and dirty at smoothing a rough surface quickly.

[Tom Lathrop]

Charlie,

I have made scrapers from old circular saw blades. They are too hard for any normal kind of sawing. I've not tried your chisel idea for breaking them out. Here is one method that does work on just about any blade up to 1/8" thick. Lay out the profile with a marker pen and grind a shallow groove on the line. Chuck the blade in a vice with the waste part exposed. Put on your safety goggles and hang a towel or other cloth to catch the flying pieces. Strike the waste piece with a hammer and it will break off fairly easily.

Don't let anyone you like very much stand near while you are swinging the hammer since these pieces fly off at a prodigous velocity.

You then need to grind the rough edge to your shape.

As Charlie mentioned, if you are going to use the tool as a finish scraper, the sides near the edge will need to be smoothed since many saw blades will have some machine grooves there. If you want it for rough work, leave the machine grooves intact.

About a million years ago I made and sold hog butchering knives from old crosscut saw blades this way for spending money.

I also make scraper blades from old or broken Japanese saws. They are thin and flexible and I have them in several shapes. They are great on convex or concave curved surfaces like a strip canoe where normal scrapers are useless. I usually put a radius on most of the corners to avoid gouging.

[Howard]

I ordered a sample of scrapers, files and burnishers today. In all, less than the cost of one sheet of Okoume plywood.

I considered Tom's idea on the saw blade, but figured the real cost is in the file and burnishers, not in the scrapers....but good info to know if you are in a bind, need one, can't wait to order one and have a defunct saw laying around.

Some of those old cross cut saws can still be found laying around, but most now have some type of pictorial scene painted on them and are hanging on a wall someplace. Would like to see those knives made sometime.

And now that I think about it, I once replaced an axe handle and was told at the time that my great grandfather was a master at that sort of work. He used a piece of broken glass to do the shaving. What's old is new? Happens all the time.

[Tom Lathrop]

Yes Howard, it's often less expensive in time and labor to buy some things rather than to make them. You miss out on the pleasure of making something special for only the investment of time and labor though. Several years ago, I made 5 or 6 knives and only put a handle on the one that is now in my belt sheath. The rest are wrapped up in a drawer. Funny thing is, I don't consider that a waste of time now.

That's partly why we are here. Otherwise we would all be buying used plastic boats which are usually cheaper than the ones we build.

[Greg Luckett]

There's the rub: time and labor. While aboard ship standing long, boring watches in the fireroom, we discovered that those boxes full of old worthless, huge files made darn good throwing knives when ground and tempered, and they were sharp enough to shave with. Bingo, we had a new hobby and I carried at least two on every boarding party. Nowadays, I have darn little time so it is better to buy stuff rather than spend the time making a tool to achieve what the real goal is: a new boat. Anyway, I hope this rambling has made some sense.

[Howard]

One of the problems with making my own tools out of saws, files, etc., is I wouldn't know how to do it if I wanted to. I don't know where you guys learned it, but most likely it was watching somebody who knew what they were doing. If Tom or Greg showed me how they did it, I'm sure I could duplicate it, provided I had the same tools they used to make the tools. The right vise, heat forge, sharpening system, etc.

The problem with learning this on your own is too much conflicting information. In researching these scrapers, I found some authors who insisted that the only way to correctly burnish a honed blade was in one direction and one direction only. Others said to go back and forth and it didn't matter. And so it goes on a whole range of topics. No really one right way of doing something....just a bunch of variations on the same idea...and all of them work to one degree or another, with only subtle changes making a huge difference in the outcome.

Sometime in the next 3 to 6 months I hope to come to NC to visit Graham, and when I do...maybe I'll be able to talk Tom into showing me ow to finish one of those knives he has stored in a drawer.

[Tom Lathrop]

Howard,

You're welcome to my shop anytime. Let me see if I remember the tools and steps used in making the buchering knives. It was around 60 years ago, so give me some slack. The main work was done in metalworking shop at school. They did not plan on everybody going to college in those days, so vocational training was the norm.

I had to break the sawblades into lengths short enough to take to school on the bus and can't remember exactly how that was done with no vice or grinding tools. At school, I drew the pattern to the customer's order and scored with a grinding wheel. The grinder was a big belt driven 8" job with no guards of any kind mounted on a post so there was complete freedom to move a workpiece around.

I mounted the scored piece in a vice, told everone to step back and swung away. Then back at the grinder, the knife was roughed out and the edge roughly shaped but not sharpened. We did have a blowtorch kind of forge/kiln?, so I wrapped the blade in a wet rag and stuck the shank into the forge to soften it for drilling rivet holes. Back to he grinder for final edge shaping and then making the oak handle and riveting with sections of brazing rod. Final sharpening with files and stone. They weren't beautiful but could go through meat and small bones with one swing.

If that sounds crude, it was. OSHA, NIOSH and interfering school administrators were far into the future. Dangerous, perhaps, but my shop teacher took his job seriously and showed us how to do each task in a safe way based on then current practice. I think we used goggles on some tasks but am not certain.

I now have stationary and portable grinders, vices, clamps of all kinds, files, plus the usual assortment of other woodshop tools but when we did not have such things, we made do with what was there. I also made fur mittens for my sisters from rabbits that I caught and tanned the skins. This is starting to get long and maudlin so, as Forrest Gump said, "That's all I have to say about that".

[Tom Lathrop]

The problem with learning this on your own is too much conflicting information. In researching these scrapers' date=' I found some authors who insisted that the only way to correctly burnish a honed blade was in one direction and one direction only. Others said to go back and forth and it didn't matter. And so it goes on a whole range of topics. No really one right way of doing something....just a bunch of variations on the same idea...and all of them work to one degree or another, with only subtle changes making a huge difference in the outcome. . [/quote']

This is both the treasure and the bane of this and other internet forums. Too many conflicting answers and no way for the novice to separate the gold from the silver from the brass from the iron from the rusty slag heap. The best way to do that is with a library card or someone you know and trust. I buy used books from ABE (American Book Exchange) on the net. Some are cheaper than the shipping charge.