How often do you need to burnish or dress a cabinet scraper?

[mjpg]

Hello, I'm new to this forum and would appreciate some advice.

I'm trying to re-finish an oak tabletop finished with Danish oil. It's had a few coats over ten years and would be good to strip it back. I'm using a cabinet scraper and it's not a tool I've used before. I have the oil coat off and want to take the wood back a little.

I seem to be able to get a cutting edge OK by filing, oil block then burnishing.

However, after perhaps 15 to 20 pulls on each edge, it seems to be blunt. I am rotating the edges so they don't get too hot. I hope I'm not working the edge too much with the burnisher and I'm trying to get a good square edge on the steel.

The scraper is a new Bahco 6 inch rectangle.

How long should I expect the edge to last?

Thanks

 

[Argus]

Welcome to the forum.

The art of scraping is well practised here and there's lots of posts over the years with differing methods.

It depends very much on the hardness of the wood, the quality of the steel and the amount of 'hook' that is turned over on the burnish............. so, it's hard to say, but personally I only file the edge when necessary.... not every burnish.

If you need to take off a thick shaving, say to remove old finish and get down to clean wood, I would recommend using a Stanley/Record No: 80 scraper plane before a card scraper. They are quite plentiful on the second-hand market and uses a thicker iron which is filed dead flat and then has a bevel of 45 degrees before you start to turn the hook. It will remove a lot of meat if you need it to without any fuss.

Finish with a scraper card. I'll leave the art of turning the perfect hook to others who will be along shortly.......

Hope that this helps.

 

[D_W]

Stripping finish, they may not last that long. I'd expect 3 or 4 times that on fresh bare wood.

 

[Racers]

I flatten the burr with the burnisher then reform it lots of times before filing it.
+1 on the Record No80.

Pete

 

[mjpg]

Thanks for all the advice and the tip about the no 80 plane, I'll check that out.

Looks like fairly frequent resharpening in to be expected. It is a big area, so perhaps I'm expecting too much.

Thanks again.

 

[Argus]

............. It is a big area, so perhaps I'm expecting too much.

Thanks again.

A No: 80 can take a cutting edge on both sides of the blade (guard the top one if you do that with some tape because it sticks up) and you can set the hook to be very agressive to begin with, then ease off on the burr later on. You'll be surprised at how quickly it will remove shavings when you get the hang of it.

 

[custard]

Hello, I'm new to this forum and would appreciate some advice.

I'm trying to re-finish an oak tabletop finished with Danish oil. It's had a few coats over ten years and would be good to strip it back. I'm using a cabinet scraper and it's not a tool I've used before. I have the oil coat off and want to take the wood back a little.

I seem to be able to get a cutting edge OK by filing, oil block then burnishing.

However, after perhaps 15 to 20 pulls on each edge, it seems to be blunt. I am rotating the edges so they don't get too hot. I hope I'm not working the edge too much with the burnisher and I'm trying to get a good square edge on the steel.

The scraper is a new Bahco 6 inch rectangle.

How long should I expect the edge to last?

Thanks

Working with Oak I'd expect four or five minutes from each edge before shavings started to turn into dust (the signal that it's time to re-sharpen), that's at least 150-200 strokes or ten times what you're getting. Bahco scrapers are pretty good so there's most likely an issue with how you're preparing the scraper.

You say it's the first time you've used a scraper so that's not surprising. Sharpening a scraper is a bit like learning to drive a car, once you've got it it's a breeze, but while you're learning you keep kangarooing down the road feeling like a plonker! 90% of woodworking is like that, you just need to keep practising and suddenly you'll crack it, unfortunately many You Tube videos tend to overlook that reality and imply instant success is possible.

Good luck!

 

[Argus]

I'm trying to re-finish an oak tabletop finished with Danish oil. It's had a few coats over ten years and would be good to strip it back.

One thing that occured to me, re-reading your post, is that you are attacking what may be an old, hardened finish.
It is possible that the friction-heat from the scraper may be depositing hard oil debris immediately behind the cutting-hook - giving the effect of blunting.
I've had thhis sort of thing happen on sappy wood in the past.
Worth a look under magnification......

 

[mjpg]

Seems like it's likely I'm not sharpening the tool correctly. I'll try a slightly different tack. I've checked out the several videos about sharpening a card scraper, and the advice on here. Seems like there's a few approaches, but even once you settle on one method, it's tricky to know how hard to burnish.

 

[mjpg]

Regarding the comment about heat and the oil finish - there was some transfer of sticky build up, but I have removed most of the oil layer now and I am down to the wood layer.

 

[Paul Chapman]

it's tricky to know how hard to burnish.

Don't turn too big a hook. If the hook is too big, it will tend to break off.

Cheers :wink:

Paul

 

[mjpg]

It was useful to get the views above. I think I had a number of problems:

* I was not forming a decent hook. Lots of videos tell you what to do, but I was trying to form a micro hook. I can see now that although small, you can easily feel the sharp hook, and I can see how the burnishing develops it.

* the old oil layers were melting to a hard sticky residue in places and this both clogged the tiny hook and probably reduced its life.

* unrealistic expectations - I did not realise I'd have to sharpen so often. I think I thought once sharpened, the scraper might do the whole table top!

The table's looking brilliant in places. Once really sharp, the finish is superb - almost shiny. Just a bit more elbow grease to go.

Thanks again.

 

[sunnybob]

Having never done any of this kind of thing, but owning a 5ft x 3ft oak table with a fair amount of damage on the top, my first thought would a power planer to remove the old varnish, than a few successive sandings with finer grit.

Apart from the "traditional" aspect, is scraping that much better in terms of finish?

 

[Paul Chapman]

a power planer to remove the old varnish

That would probably remove most of the table top as well :shock:

Cheers :wink:

Paul

 

[Tony Zaffuto]

Regarding a card scraper, first you must have the edge square, then polish edge & sides, being careful to not round the edge. On the side run your burnisher a few times, so the burr is an extension of the side, then set the card upright and using your burnisher, roll the burr to the angle you want. Most important is to have the edge square and not rounded at all.

If you know how to draw file, you can file the edge square, and, depending upon how coarse your file may be, have a sufficient burr to imediately work. Main issue with scrapers is over thinking a simple task, one for which extraordinary gadgets are not needed: just a file, stone and something to burhish with.

 

[sunnybob]

a power planer to remove the old varnish

That would probably remove most of the table top as well :shock:

Cheers :wink:

Paul

OK, computer error there. I actually meant power sander, honest!

 

[Wuffles]

Sounds like you've got it sorted now, just in case...

I bought one of the carbur burnishers from Workshop Heaven and every time I use it I am relieved I did (I also have to watch the YouTube instructions each time too) because I'm just not very good at maintaining anything at all. If it helps, the Workshop Heaven video on its use is very good - Matthew's on here too I think.

https://www.youtube.com/watch?v=MmvpqtDEDSE

 

[MIGNAL]

If I want a 'very fine grade' scraper I don't work the edge, just get it square and finish at around 800G. The edge is turned over with extremely light pressure. If your scraper has a sharp edge to begin with it takes very little to raise the hook. For more everyday use you can stop at a much lower grit and use more pressure.

 

[yetloh]

+1 for the Workshop Heaven burnisher. If the cabinet (card is American) scraper is properly prepared this will create a lovely sharp hook in two diagonal strokes - one with the scraper flat on the edge of the bench to pull the metal up and the second with scraper vertical in the vice with the burnisher at a little less than 90 deg to the edge, to pull the raised metal over to form the hook. I have never used a file on a scraper - all that is needed is a fine diamond stone to polish the faces and the edges with the aid of a square wooden block to keep the edge square to the stone. Remember also that you can get four long cutting hooks per scraper. It works very well for me.

Jim

 

[ED65]

* unrealistic expectations - I did not realise I'd have to sharpen so often. I think I thought once sharpened, the scraper might do the whole table top!

With a film finish you might have been able to actually!

There's a warning above about a too-large burr having a tendency to break off, although that is true a bigger hook is generally to be preferred for finish removal (the idea being I think to sort of scoop from underneath the finish). Danish oil is a bit of a pig here though since it's a penetrating finish so you're removing finish-impregnated wood which make it akin to scraping resinous wood species, so quite a bit tougher that if you were dealing with shellac or varnish.