Thread: Cabinet Scraper woes.

Screwdrivers are generally not hard enough for modern steels. The best burnishers are a carbon rod (old router bit shaft).

It is important the the edges begin flat, smooth and square. The other important factor is to draw out the steel before a two-stage turning of the hook.

I have this documented in a pictorial here: http://www.inthewoodshop.com/Woodwor...29Scraper.html

Regards from Perth

Derek

Link didn’t work for some reason Derek!

Edit: Nevermind, just a tapatalk problem.

O/K for me.

Actually yeah I just did some testing and it looks like it’s a Tapatalk bug. Carry on!

Originally Posted by redx

Hi,


I don't have a proper burnishing tool but this bloke says

I have never forgotten a trade school teacher telling me the same thing ! He was paid to teach us Cabinet Making??

He was great but he actually wasn't up on the good ways to work with solid timber this way and had spent many years on Kitchens and laminex work. He suggested the screwdriver or chisel back .. yeah!! forget that .

The rod Derek is showing will be good . Make sure its a solid carbide bit though , if its a router bit . And not the type with Brazed on Tungsten Carbide cutters . The shaft of those wont do .

I was shown to make my own if you want to get into that . Any old triangular file will work if you can heat it to a good red hot . If you don't have the heating capabilities and a way of shaping it quickly like a bench grinder or better a linisher and buff then your better off buying the burnisher rather than make it. If you want more details on how to do it then ill put the details up here . Just let me know.

Your guy in the link recommends a diamond plate rather than Oil stones and Water stones. I don't agree with him on " Do not use Oil stones" . Its all Ive ever done it on and its never been a problem . I do have some nice quality Oil stones though and not the new stuff.

If your doing all of what the guy in your link says and what Derek is saying then your real close so stick at it and you will soon be shaving away .

Just get that burnisher sorted, 1 .

And 2 . I like applying a bit more pressure with those three passes turning the edge.

Rob

Another cheap tool for doing this is an old engine valve from a cylinder head if you can find one. Cut the head off and make two wooden handles for it as the shaft is a bit short and you ready to do some work.

I once did something like that, Chris.



Of course, I wasn't really serious at the time.

Regards from Perth

Derek

I've always made my scrapers from a piece of old handsaw (Disston) and used a nail punch to run the burr. The edge needs to be dead square and sharp before burring. Never had a problem.

If there is any subject that has more 'how tos' than sharpening in general, it has to be scraper preparation! But like sharpening, the aim is very simple, you are trying to make a straight, square very smooth edge and turn a small burr on the corners of that edge. There are many ways to achieve this, all equally successful in practised hands. I used to use my oilstones, but it's easier with diamond, and less likely to gouge the surface. I certainly wouldn't try it with water stones, but perhaps if you are very skilled and careful you could? When preparing a scraper quickly for rough-ish work, I simply file it (with a 'smooth-cut' mill file) - give it a few strokes with the file held in both hands like a spokeshave (draw-filing), then finish with a few light strokes with the file placed along the edge & held square to the surface with your fingers, like using a jointer. If your file is fine & in good condition, this will give you a pretty good edge, but for fine work like finishing veneers, etc, you really do need to go the full bit & 'polish' it on finer media of some sort.

I beg to differ with Derek & Rob, you can use a screwdriver shaft to form the burr, I did that in happy ignorance for a good many years when I started using scrapers, because that's what I'd read somewhere - but they aren't the best tool for the job by any means. Tage Frid advised using the back of a chisel, which is usually harder and a bit smoother than the shaft of a screwdriver. Indeed, screwdrivers are about the same hardness as scraper steel, and the results can be a bit hit & miss, particularly when you are new to the business. My go-to burnisher these last 20 years or so is made from a piece of polished 1/4" HSS rod. I think it's M2, but can't swear to that, but whatever it is, it's turned thousands of burrs and is as bright and shiny and unmarked as the day I got it, so I'm more than happy with it.

The main ingredient to success is perseverance. Keep trying, and adjust the angle you're holding it at slightly until it cuts. The most common fault I find newbies make is they overdo the burr, by which I mean rolling it over too far. Hold the burring tool around 10 degrees off vertical at the most, and 3 or 4 firm strokes is usually plenty. However, our idea of 'firm' is variable, and it also depends on whether you are using a round or flat-surfaced burnisher - a round burnisher concentrates the force over a smaller area, while a flat or oval one spreads it a bit & will require more presure for the same result. Rolling the burr over too much is like putting too steep a bevel on a plane blade, the cutting edge can't contact the wood properly, and the result is either nothing, or dust, & certainly, irritation on your part. Try holding the scraper at ever-diminishing angles to the surface you are scraping, if it starts to cut when it's laid over at a very acute angle to the wood, then an over-done burr is the problem.

Stick with it, it will happen suddenly & lovely rolls of fluffy shavings will come off your scraper like magic. Then it won't happen the next time you try it, but after a bit, you'll get it all sorted & you'll wonder what the initial fuss was all about. Do be aware that some woods just don't scrape well whatever you do, particularly soft ones like Aust Red Cedar, and Softwoods in general (rough rule of thumb is, the harder the wood, the better it scrapes). It's one of those highly satisfying experiences in woodworking when you get a card scraper to work properly for the first time - you'll never look at sandpaper in the same light again!

Cheers,

I agree with the above re. good preparation of the edge, although I've always used a round carbide tool to create the burr.

Biggest single issue I had (and Ian has mentioned above) was applying far too much pressure when rolling the edge. A smaller burr at the correct angle works far better than a huge hook on the edge that can be seen from space. A burr that you can barely detect when running a finger across the edge gives the best results IMHO. I'm sure you're aware of the old "fridge magnet stuck on the back" trick if the scraper gets too hot for your thumbs after extended use?

Ian, regarding the use of screwdrivers as a burnisher ... sometimes the steel in the scraper is too hard for the steel in the screwdriver (this may be due to the tempering of modern steels in new scraper), and sometimes the steel in the screwdriver to too soft for the scraper (modern screwdrivers may have a soft shaft and a hard tip). Anytime one have to press hard with a burnisher to turn a hook, it is likely to be the wrong match.

We should push the use of "proper" burnishers that will work rather than the use of objects that resemble burnishers. These tools are cheap, and a good burnisher makes the task easy. A poor burnisher is an exercise in frustration and disappointment.

Regards from Perth

Derek

Originally Posted by derekcohen

I once did something like that, Chris.



Of course, I wasn't really serious at the time.

Regards from Perth

Derek

It simply works and I am serious.

Ian gives a very good summary and word picture of the process but I might add a bit more if I may. 10 degrees is is not much and a good way to get the concept is to use one of the digital angle gauges available from Ebay for $20 or so or cut a piece of wood with a 10 degree slope on it and by putting a slot in it perpendicular to the 10 degree face and close to the depth of the scraper you can slip the scraper into the slot and hold the burnisher to match the angle. Put the block of wood complete with scraper trapped in the slot in a vise to hold it and away you go. You will soon get the idea and use the piece of timber for firewood. Doing this might save a bit of frustration and swearing which is always good.

I often use a card scraper in my videos on youtube and I get asked how do I sharpen them and could I make a video about it. I probably will, but it will just repeat the tried and true methods from old and be just another video about scrapers. The biggest issue I see with creating a decent working edge is the drawing out of steel process. People get hung up on turning the burr and polishing the edge, but really those two processes are probably the easiest that you can just do with or without experience or training or intelligence. But drawing out steel can be done wrong without appearing wrong at all.

I've tested this myself and I find when I draw out steel using a burnisher held at 90° or less (acute) to the edge face of the scraper, I don't end up with a good edge at all. But when I draw out material with the burnisher held at more than 90° (obtuse), usually I go for about 135°, it actually draws the material out. Without nerding thungs up and getting a microscope, I'd take a guess and say that drawing out using the burnisher at an acute angle, it does in fact draw material out but then instantly rolls it downwards back on to the edge face. When you then try to turn the burr outwards, any pressure you apply to the burr simply folds it back onto the edge face of the scraper. And you end up with a freshly micro arrised edge which will create dust when forced but not much in the way of shavings.