Cutting slots in the end of 4X10 timber
Help! As a long time lurker here, I turn for some much-needed help regarding my house / roof renovation. It’s an old adobe here in santa fe, and I’ve poured new concrete bond beams to set new roof timber on. My problem is that I got myself into a bind by designing a “knife” type steel plate connector for my 4X10 to 6X12 connection in a few areas, and now need to cut 3 1/2″ deep X 9 1/4″ tall mortises / slots into the end of the 4X10’s. I’m not doing enough of them to merit spending the money on a nice chain slotter, but am doing enough that I am worried about how awful and slow the first attempt was, using all the typical tools an advanced DIY’er has….. 7 1/4″ circular saw (only about a 2 1/2″ depth to the cut), HD Jigsaw (no comment), Sawzall with 12″ blades (yikes!), a nice 1/4″ chisel (kinda short ‘blade’ though), a pull-saw, and all the other usual assortment of drills/bits/router/etc.
With the circular saw and a jig, I’m at least able to trim the ends clean and square by flipping the timbers over once, but for the life of me I can’t figure a good time & cost effective way of making these 1/4″ wide vertical slots! The timbers range from 14 feet to 16 feet in length, so standing ’em up and running ’em throughthe table saw doesn’t seem prudent 😉
Maybe a jig for those monster Sawzall / blades? My next try will be drilling a 1/4″ hole at the back of the slot, and trying that – then cleaning up the round edges of the hole with the chisel. Somehow I get the feeling I’ll not have a whole lot of luck guiding the Sawzall through 9 1/4″ of wood all the way back to that hole!
Replies
Look here:
http://www.praziusa.com/beamcutter.html#
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Rebuilding my home in Cypress, CA
Also a CRX fanatic!
I have used the Prizi and it would work for tour job. However, it won't work on all circ saws. Be prepared to spend about $300 for both items. An alternative is to use a chain saw with a steady hand. LOL
Possibly, a bandsaw could do the job. Have to be a big one tho.
I would drill the slot, then use a router with the longest carbide bit you can get, and a chisel to clean up the rest. Use a drill press for the drilling, or at least a jig of some sort.
One thing you might want to consider is just cutting it from both sides with your skill saw and cleaning up with a chisel. You can either just leave it exposed on the visible edge or cut it really clean and dutchman it. A variation of this would be a base for a chain saw.
Another option would be to drill out the majority of the waste with a 1/4 or 3/16 bit and then pare out the rest.
At the timberframe shop, we have a slot cutting bar for our chain mortiser and we also have a plunging rig for a chainsaw. But we have done it with skill saws, tool.
I hate steel.
Glen,
Chainsaw. Why piz around?
Clamp a piece of 3 x 3 or 4 x 4 steel angle to the side of the bar with a bloody big C-clamp and some spacers to keep that steel away from the chain. That will set the depth and help keep the cut square. Drilling through the bar and angle and bolting this arrangement together would probably be better as vibration can shake a clamp loose.
Ron
My Festool jigsaw with the S 145 4 FSG blade goes through PT 4x4 easy as pie. Might be worth a try.
The awful thing is that beauty is mysterious as well as terrible. God and the devil are fighting there, and the battlefield is the heart of man.
- Fyodor Dostoyevski
GLenz,
Drill a series of holes along the place you want the slice. If you use a 1/2 inch forsner bit you can safely overlap the holes and remove even more material without the bit wandering into the adjacent holes. Once done with the series of holes connect all of them with a well sharpened chisel (dull ones are too much work, and terribly inaccurite). To sharpen chisels without spending a great deal of money or ruining your chisels with a bench grinder that won't really sharpen them well use the scary sharp method.
Scary sharp is something I learned from fine wood working.. What you need is a few sheets of wet or dry sand paper. Star out with something like 220 grit go to 320 grit then to 400 and finally 1000 grit.
Put the paper on a piece of glass put a few drops of oil on the glass to make the paper stick to the glass and then add a few more drops to the sand paper (220grit) to form a slurry. hold the chisel at 30 degrees and rub briskly back and forth in a few minutes there should be a nice even smooth face on the top of the chisel, flip the chisel over and holding it flat do the same on the back side,, now go to the next grit 320 grit repeat, then do 400 and wind up with the 1000 grit.. you will be able to shave with it.. and I can resharpen all of my chisels during the commerical breaks on my favorite TV shows.. If they are really dull I might need to take two commerical breaks..
30 seconds with a chainsaw, maybe 50 on the first one!