- 22 September 2016 at 1:52 am #140567
Hello! I am new to hand tool woodworking. Loving every minute of it. But I have run into a few small issues with my housing dado joints. One problem in particular is puzzling me. There are several factors at play here but the basic problem is that after I create my knife wall and start chopping down, I always end up fracturing the wood right before I get to my depth line. I have been using strictly “white wood” from Lowes. So, I figured maybe I was hitting the chisel too hard and that was causing the fracture. However, after hitting considerably lighter, I am still having the same result. Now one thing that I think may be contributing is that I don’t have a good workbench. It is a heavy wood door on top of a wooden table but the table legs are thin metal. So, in other words, there isn’t a lot of support underneath the table and I think there is just too much energy being wasted and in order to chop well, I am having to strike harder. I hope that what I’m saying makes sense. One other thing to mention is that I do use the method of chisel sharpening that Paul teaches and my chisels are RAZOR sharp. I’ve attached a pic of the fracture. You can see my depth line from the marking gauge and how the wood is fractured not too far from it. Hopefully you can see what I am talking about. I’d love to hear your thoughts and advice! Thanks fellow woodworkers!
You must be logged in to access attached files.22 September 2016 at 3:16 am #140579jbtheppParticipant
If you aren’t making a knife wall on the side of the board just as you do on the top then this fracture will happen. At least that is what I figure out the hard way.22 September 2016 at 11:15 am #140586BrianJParticipant
In a few videos Paul talks about both harder and softer (dense or less dense) aspects when working white the ‘whitewood’ like pine etc. Ive also found the knifewall down the face of help, as well as small bites.
Hope that helps,
Ontario, Canada22 September 2016 at 1:32 pm #14061422 September 2016 at 7:38 pm #140749jbtheppParticipant
I can’t recall which species of wood I was working when I realized it. I would imagine that this would happen with all species of wood under the right circumstances. In addition to the knife wall I also never make a chop with the chisel hanging off the edge of the dado. I always stay away from the edge about 1/32″ when I chop and then lightly pare down with the chisel to finish off the end. This seems to work well for me because the end of the dado has nothing to support it.
The knife wall always helps me. Paul often says “the knife wall separates the wanted from the unwanted.” I have realized that all my tools do this but boy the knife wall does it much cleaner.23 September 2016 at 2:26 pm #140812RenoParticipant
Normal chisels have a 30° bevel. Paring chisels generally have a 20° bevel, and can help with this sort if wood. No hammers with paring chisels.25 September 2016 at 7:11 pm #140850kevinjamesParticipant
I generally don’t chop all the way to my line. I leave a small bit and get my final depth with a sharp knife. I usually have to cut those bits away after I use the hand router because they are still connected right in the corner. Seems to work for me. Good luck.
Kevin3 October 2016 at 9:11 pm #141150Hugo NottiParticipant
Perhaps your blows are too powerful for the sharpness of your chisel. Only so much power can go into a clean cut, the rest is wasted elsewere, for example in compressing the wood. It might help to chisel directly above one of the legs of your bench-table. If that doesn’t help, make a test on a strong floor (directly, not the table on the floor, but your workpiece). If that doesn’t help either, you will have to reconsider your concept of sharpness.
On your picure, an annual ring has been pushed down, creating stress in the surrounding wood. I think, that this actually caused the tearout. Therefore, I do think, that your chisel is not sharp enough. It took me two weeks or so until my chisels were ready for clean crosscuts. I have to admit, I lied to myself about the sharpness for a while, but I got better every day.
PS: On this particular piece of wood, is the annual (dark) ring going almost parallel to the visible surface? Just curious, it has nothing to do with the general problem.
PPS: I started with a flimsy workbench as well, and I had exactly the same problem, in my case on dovetails, where the chisel is the only choice (except for a coping saw). While I really thought my chisel to be sharp, it was not at all, as I know today – a few weeks later.
4 October 2016 at 5:30 am #141157ehiseyParticipant
- This reply was modified 4 years, 2 months ago by Hugo Notti.
Going to second Hugo on it looking like your chisel is either a bit dull or the bevel is more than 30 degrees. Or if really razor sharp you are driving too deep on the chop because most of that chop is not actually cutting the wood at all. The tearing looks like it is starting more than half way up the knife wall.
Lung T'an Hu Huesh Kung-fu Woodshop12 December 2016 at 1:04 pm #143251
Thanks @jbthepp @reno @kevinjames @hugonotti @ehisey for all of your responses. I meant to reply sooner but haven’t been able to be in the shop much over the past few months. I’m just now getting back to it. Still struggling with the housing dado. I will take your suggestions and put them to the test!
@hugonotti @ehisey you might be right about the sharpness/degree of bevel. I’m not sure about that but I’m humble enough to say it is possible I need to work on those things. My chisels will shave the hair off my arm with ease and they will also push through a piece of paper with ease. But maybe something is off.
Hopefully I’ll be able to stay in the shop more from now on! I’ll let you know how things progress for me. I’m determined to perfect these dados!
13 December 2016 at 12:19 am #143281Hugo NottiParticipant
- This reply was modified 3 years, 11 months ago by John Phillips.
In the image, you are getting to the reddish line, which is pushed away. And there is more red appearing at the cut. Perhaps you just have a difficult piece of wood, mix of soft and hard fibres. Perhaps, it would be possible to prevent the tearout on such areas by pre-cutting with the knife. Soft wood seems easy to work with because it can be separated so easily. But when I started using oak (just small projects, but real oak), I noticed, that oak is much easier. It takes longer to chop, chisel or saw, but it seems more predictable. And maple is even nicer, I bought a small piece to make a mortise gauge and replace some small parts on an old desk. Of course, there can always be nasty grain, and I consider that part of the fun, if it isn’t too bad. And there is white wood and white wood. Some wood is as week as a cookie. In short: It is pretty hard to get perfect housing dados on soft wood.
And you should test the sharpness of your chisel right after a tearout, just in case.
Dieter13 December 2016 at 1:47 am #143286
Thanks @hugonotti. Great advice. Good news! I cut a pretty clean housing dado tonight. I placed the wood on a better bench, slowed down a bit and didn’t strike as hard on my chops. I also used a knife wall on the outside. No tearout tonight. Now for my next challenge. I just can’t seem to get the poor man’s router to work very well. If I can conquer that I’m in business. I’d like to
buy a hand router but they’re a bit pricey it
seems. Might have to wait a bit on that one.13 December 2016 at 7:26 pm #143325deanbeckerParticipant
The poor mans router and the hand router do the same thing. Try taking shallow cuts with the poor mans of a tho or two and see if it isn’t better
A sharp chisel is absolutely necessary. And it is possible to put too much camber n a chisel just as it is easy to round over the edge.
Lay your chisel flat, like you would if you were paring, and see if it grabs if you have to go over 2or 3 degrees above flat the edge isn’t quite right,
Sharp and sharp and your two best friends and remember also Paul says to sharpen when you need to not when you want to.
I actually noticed that today on a boxes dovetails it was whisking off the edge of the pins then it wasn’t shiny on the next one , sharpened it and the shiny returned. This is in pine
- You must be logged in to reply to this topic.