Thickness of card scrapers

  • This topic has 14 replies, 6 voices, and was last updated 6 months ago by Ed.
Viewing 15 posts - 1 through 15 (of 15 total)
  • Author
    Posts
  • #748401
    Kory Karr
    Participant

    Wondering if anyone knows what thickness is ideal for a card scraper. I have one that is very stiff and wondering if it’s abnormally thick. Is it possible I have a cabinet scraper blade instead of a card scraper?

    #748417
    Larry Geib
    Participant

    It depends on what you want to scrape. The gold standard for flat surfaces is the Sandvik/Bahco 474 line, which measured .032” (.81 mm) .
    A crucible tools curved scraper I have measures the same..

    I also have a shorter Bakco that’s .6 mm and there isn’t much difference than using the longer,thicker ones.

    But that’s too stiff for curved surfaces, and scrapers for profiles come in all thinnesses to acomódate special cases.
    The really thin ones I have are only really any good for detai work on curved surfaces.

    • This reply was modified 6 months, 1 week ago by Larry Geib.
    • This reply was modified 6 months, 1 week ago by Larry Geib.
    #748418
    Darren
    Participant

    Post a photo and we can have a look.

    Card scrapers do come in different thicknesses, perhaps you just have one at the thick end?

    #748518
    Ed
    Participant

    You’re going to want a selection of thicknesses anyway, and it helps to have a couple on hand even if they are the same thickness. So, I’d suggest just buying a few of varying thickness and trying them. 0.032″ is common, but I like thinner, too, especially when trying to get a smaller area. Of course, that also means you can dig a hole if you’re not paying attention.

    #748522
    Colin Scowen
    Participant

    I bought a set of 3 and a single scraper from Buck & Hickman one time when I was in the UK. They have served me very well. The single scraper is thicker than the three set. Yet to find a consistent way to set up the concave curves though.

    Colin, Czech Rep.

    #748525
    Larry Geib
    Participant

    Chris Schwarz posted a good curved scraper pattern I’ve found quite useful .
    WHe also sells a good scraper with that shape on his website. It’s great for chair seats.
    He got the pattern from chair maker Chris Williams.

    And Paul has a tutorial on shaping scrapers to any curve:
    https://paulsellers.com/2013/09/shaping-sharpening-round-scrapers/

    C86E1A18-FA9F-48A8-9D44-0EDC6546327A

    #748588
    Ed
    Participant

    To turn the bur on a curved scraper, I often use a nail set while clamping the scraper in the vise. The set isn’t the ideal, polished metal you’d wish for, but it helps me for two reasons. First, it is tapered. This means I can bear straight down yet still be applying pressure at an angle to the edge. This makes it easier for me to follow the curve. Second, the diameter is quite small, which means less force is required to generate adequate pressure. There must be better ways, but this is somewhere between passable and good.

    #748816
    Sven-Olof Jansson
    Participant

    Her most gracious request for a sideboard in sugar maple (Acer saccharum) has provided me with a lot of experiences from the use of various scraping tools.
    Scraping tools
    The upper part of the inserted photo shows a piece of said wood with unruly grain; the bottom part is of the tools tried on it. Overall, the scraping plane worked best for me, giving no issues going along the board in either direction. Then followed the cabinet scraper, which was worked without a hook on the edge. In the hands of someone more accomplished, it would perhaps have been the best tool.

    Of the scraper cards, the Crucible (0.81 mm) was very effective, with little tendency to dig down along the corners of the edges. Thanks to its shape, it didn’t require any flexing. The card scraper holder has a 0,81 mm Veritas scraper inserted. My thumbs prefer that combination a lot above flexing the 0.81 Veritas card next to it. The short one, third from right, is a Bacho 0.61 mm. Mine have all come with good hooks, ready to use straight away, and not too hard to flex. As long as I shy away from upcoming opposing grain along the edges, they have done a good job.

    Last to the right are a 0.52 mm Lie-Nielsen card scraper and a 0.41 mm Veritas; very good for details, and I don’t think they are intended for work over any larger surfaces, with the exception of scraping finishes like shellac.

    The HNT Gordon with its 60º bed angle worked well enough as long as the grain didn’t rise up against it. The little Veritas bevel up smoothing plane quickly retreated to the rear, leaving issues behind.

    In summary and as usual, I think the best scraping tool is the one that one first achieved good results with. The Crucible, Bacho, and Lie-Nielsen are to me a good combination.

    Sven-Olof Jansson
    London, UK; Boston, MA

    #748872
    Ed
    Participant

    Sven-Olof, I know your comment is about scraping (and very helpful!), but have you tried a Bailey style plane with the cap iron pushed very, very close to the cutting edge and light shavings? Also, at those knots, try applying a quick wipe of denatured alcohol a moment before planing. Those knots may plane if approached from two directions with a sort of circular motion so that the apex of circle is tangent to that impossible to cross line where the grain reverses. Planing may very well be impossible, but sometimes those tricks make the difference for me.

    • This reply was modified 6 months ago by Ed.
    #748949
    Sven-Olof Jansson
    Participant

    Thanks Ed,

    Just back with a set of maple boards that promise to further challenge me; so your suggestions are very timely.

    Will try to nudge the cap irons yet closer to the edges of the blades. Then, it’s time to concede and add secondary bevels. There must be more to planing than shaving along the fibres, and an additional 5° of bevel, I suspect contributes. I will remember to follow your method of also give the primary bevel ago when sharpening, just to keep the secondary one from growing too wide.

    I try to approach the chaotic areas around knots from various directions and angles, will add the circling you mention, and scribble where the grain reverses.

    The treatment of knots with denatured alcohol is only too intriguing to not be tried. There’s truly a lot more to wood than what is known to my philosophy.

    Thanks again.

    Sven-Olof Jansson
    London, UK; Boston, MA

    #748954
    Colin Scowen
    Participant

    I tried (and now use) Paul’s suggestion to keep the mouth choked full of shavings to help on awkward grain.

    Colin, Czech Rep.

    #748987
    Ed
    Participant

    The denatured alcohol is pretty much witchcraft. I don’t remember why I tried it and cannot prove it helps, but it seems it might. Just use a light wipe. You don’t want the wood to be truly wet and soggy.

    I know Paul says the cap iron is not a chip breaker, but I’ve watched detailed videos from experiments done in Japan and am convinced by them that the cap iron does act as a chip breaker and find that pushing it as far forward as I dare helps. It does make the plane harder to push, though, so be prepared to lubricate the sole.

    Another trick with complicated grain is to plane across the grain instead of with it to get close to dimension and then go with the grain as little as possible with very fine shavings. Of course, be very careful with spelching. If there are knots, this won’t help much, of course.

    Or, the heck with it all, and just grab the cabinet scraper, especially when it seems that’s where you’re going to end up in the end anyway!!

    #749014
    Larry Geib
    Participant

    Sometimes the trouble planing or scraping around knots and rising grain is that the fibers coming out of the wood in wild grain aren’t well consolidated and resembles the end of a broom on microscopic scale. You won’t get good results regardless the work method if the fibers move around.
    I have sometimes been able to get good results by flooding the area around wild wood with thin CA glue or even shellac before planing.

    It doesn’t seem to affect staining the wood, as fresh fibers are exposed during scraping or planing.

    The first time I did this was years ago on my workbench, when in desperation I used I part West Sytem epoxy thinned with 2 parts acetone.

    I’ve never had an issue again with the area despite several rescrapings of the top.

    #749100
    Sven-Olof Jansson
    Participant

    Colin, Ed, and Larry,

    Thanks to all of you!

    With the memory of a semi-domesticated black hole, I had of course forgotten that packing the throat helps. Fortunately the very tight mouth, and the chip-breaking cap iron{1} now a gnat’s whisker from the blade edge, did it to a degree.

    Could it be that the strong hydrophilic property of concentrated alcohol induces a localised additional drying, making the fibres brittle and more amenable to planing? The trick worked very well today. I conceded on dimensioning the maple by hand, and, at the very fair price of 8 cinnamon rolls and four Budapest pastries, saw it done by the local cabinet maker, whose machines had no problems at all – except for a knot, which yielded after ethanol intoxication. (The 13.1 board feet of maple had set me back $160; clearly calling for something roborating, though of less potency and not denatured).

    The use of cyano-acrylate or West System + thinner is another addition. This far I’ve only applied the former to end grain when cutting tail recesses for half concealed dovetail joints. It really helps at preventing splitting, tearing, and spelching.

    Discretion being the better part of valour, smoothing was done with a #112 and a cabinet scraper; sooner sacrificing some glossiness than failing at repairing with the Novoryt wax system.

    Thanks again.

    {1} I believe plane shavings curl into spirals due to a “continuous breaking” of the surfaces facing the cap iron or bevel (in the case of bevel up planes), resulting in non-homogenous tension of the shavings, inducing spiralling. That friction induced heat and drying would result in a moisture gradient and spiralling, seems less tenable, I think.

    Sven-Olof Jansson
    London, UK; Boston, MA

    #749155
    Ed
    Participant

    Glad it helped. Maybe there is something to it and it is more than my imagination. I’ve wondered if the alcohol modifies the lignin or maybe simply acts as a lubricant. Another trick that helps is with regard to times when, for some reason, there is trouble having the plane enter the cut at the near end of the board. If it isn’t contrary to the final piece, e.g., because of thickness reduction or length reduction, I’ll put a slight chamfer on the end of the board and give a quick wipe with my equivalent of Pauls’ rag in a can. This helps the plane enter the cut instead of scudding. If the chamfer isn’t possible (and it is just a tiny one!), applying the oil still helps as does alcohol. You probably noticed that the alcohol doesn’t last long, which might suggest it is lubricity rather than reaction?

Viewing 15 posts - 1 through 15 (of 15 total)
  • You must be logged in to reply to this topic.