I have a set of Irwin chisels. My shapening method, which I always have had great results, is will a flatened piece of granite, wet paper, Veritas MkII guide, and honing compound for a final pass. I sharpen them all at a 25 degree bevel.
As I said they are razor sharp and so far with this set I done mostly paring and some light cross grain. I recently had to use them to chop out the waste between 2 tenons on a wide board. After only about 8-10 strikes the edge was completely gone. The steel rolled over onto the flat side of the bevel and I could see some nicks in the edge when held up to a light.
My question is, does anyone think this is mostly the steel of these low end chisels or the bevel. I realize that mortise category chisels usually have a 30-45 degree bevel but I would think that at 25 degrees ( a good all around bevel), mine should have stood up longer.
Replies
Hi, 25 degrees is a good choice for chisels used in paring--hand pushing only--and light mallet taps but it is too acute for whacking the chisel. At least for the Blue Chips and other in the same price range.
If you have had success in edge retention when using them for paring, consider getting another set and grinding a steeper bevel for choping. Undoubtedly, chisels with better steel can be bought. But if these have fit your needs, get another set.
If you do have extra cash laying about, consider another brand. The AI chisels from Tools for Working Wood are decently priced and can take pounding on. As well, I have heard good things about the Hirsch such as Lee Valley sells, and they are a bit less than the AI chisels.
Take care, Mike
I would expect your chisels to be junk. That said, we shouldn't rule out technique.
I don't think we should think in terms of right or wrong technique, but there certainly is technique that is easier on tool edges. For example- recent articles in FWW discussed using chisels as pry bars, levering out chips, heavy mallet blows, etc. I find such techniques are very hard on chisel edges and generally unnecessary.
In your case, you may have been able to do that job with lighter and fewer taps. When wood doesn't immediately jump out of the project, greater force isn't usually the best alternative. I impose a 3 hit rule in my shop. Usually after three hits, chisels cease to be chisels and become wedges. So you cut down 3 mallet taps, then pare away the stuff riding the bevel, then more hits and so on. There is no levering- no need for dead blow hammers. If you find you need unbreakable handles on your chisels, that may be an indication that you are hard your your chisels. I don't think there's ever a time when a scraping/prying action is needed or a good idea.
So you may find your problem goes away with better chisels or higher bevel angles. But to some extent, better chisels let us "get away" with technique that's hard on chisels. Imagine how well you'd be able to work with really good steel, if you learned to work with your soft Irwin chisels.
Adam
Unfortunately, the newer Irwins/Marples are made from soft and brittle steel, the edges will only hold up cutting butter. Too bad, the older Marples were a good value, the new ones are useless.
Beat it to fit / Paint it to match
Ha, ha, hammer! Which is it? Soft---- or brittle? Surely it can't be both? Slainte.Richard Jones Furniture
I think Hammer was saying the steel is so bad the usual trade off giving up soft but tough to get hard but brittle wasn't applicable. In otherwords--dreck.
Could be Steve. Could be. I just found it funny. My sad sense of humour I guess. Slainte.Richard Jones Furniture
Hey Richard,
I know those terms are often a contradiction when it comes to cutting steel but the Marples edge not only bends but it cracks up too. It could be a lamination, I don't know, but they are pretty useless if you aren't cutting butter or slicing cheese. I have a pic of two older Marples on the right and a wide one on the left. One light strike and the 1 1/4" was done for.Beat it to fit / Paint it to match
Well, hell's bells hammer. I guess it's possible for a chisel to be both be brittle and soft. I can't think I've experienced the problem you describe, although I've heard others say similar. Slainte.Richard Jones Furniture
Might help if I posted the picture, duh!Beat it to fit / Paint it to match
It may be only me hammer, but the edge on that wide chisel looks more rolled over than chipped, which tends to hint at softness more than brittleness. If the steel were brittle I'd expect to see a jagged opening in the cutting edge, or a corner chipped off.
In either case, if the force applied was rather slight then it's a problem. On the other hand cutting down vertically into the face of a piece of very hard wood across the grain is hard work-- if you can find a way to divert the energy a bit through creating a slicing action that can help. That's exactly what's done with mortising of course where the beginning cuts are in the middle of the mortise the chisel being leant over a bit to cut rather with the grain.
And of course those bevel edged chisels aren't well suited to heavy pounding, as their role is light trimming. Slainte.Richard Jones Furniture
I agree. I have two sets of Ash Handled Marples and one set of Ash Handled Firmer chisels from Marples, about 25 years old, and I often pound on them and have no gripe with their ability to hold an edge.John
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