Advice on Centering a Beam

[redoak]

Hi All,

Just getting started with chainsaw milling, did my first three 8x8" beams last weekend. They came out well, but I am wondering if you all have any tips for better centering the beam within the log.

What I've been doing is setting the slabbing rail the same distance from the heart on both ends. I figure that will avoid running out the taper on one side. But then even though the logs look fairly straight, I got two beams where the wain was pretty significant on one side. I thought I had 4" on each side of the heart (to make an 8x8) but it still ran out in the middle of the log.

Any tricks to lining up the cut to best avoid wain? My logs are all 12" or greater, so at least on paper there's a nice 8x8 somewhere in there!

Thanks.

 

[woodshop]

What I've been doing is setting the slabbing rail the same distance from the heart on both ends. I figure that will avoid running out the taper on one side. But then even though the logs look fairly straight, I got two beams where the wain was pretty significant on one side. I thought I had 4" on each side of the heart (to make an 8x8) but it still ran out in the middle of the log.

When I have a lot of taper, as in the pic below, and I do not want to slice the log from one side that way (sometimes you do for certain figure etc) then I do what you do. I measure from the pith of the log, which might not necessarily be the center, to the guide beam (slabbing rail) and adjust the height on either end accordingly so it parallels the pith as close as I can get it. For one thing, this assures that you don't have too many boards with that center of log pith area in them, as that often tends to be lesser quality wood. Of course we are assuming the log is fairly strait. If that is not the case then you just have to wing it and use common sense to try and get the best slices. To do what I am doing in this pic with the guide higher on one end to compensate for the taper, you do need a way to adjust the height of your rails and still attach them to the log securely. I use the guide rails that came with my Ripsaw bandmill which make that fairly easy. With home made rails or a ladder, you will have to get a little creative, maybe a movable end piece that slides up or down, something like that. I am sure one of the other milling guys (gals???) that use that type of rail will chime in on that.

Although it doesn't look like as much in the pic below, this log was 42 inches on the butt end, and only 35 on the other, lots of taper. Because I wanted to get some quartersawn figure, I made sure I cut out the taper by doing what I explained above. You can kinda see that in the pic.

 

[trimmmed]

When I have a lot of taper, as in the pic below, and I do not want to slice the log from one side that way (sometimes you do for certain figure etc) then I do what you do. I measure from the pith of the log, which might not necessarily be the center, to the guide beam (slabbing rail) and adjust the height on either end accordingly so it parallels the pith as close as I can get it. For one thing, this assures that you don't have too many boards with that center of log pith area in them, as that often tends to be lesser quality wood. Of course we are assuming the log is fairly strait. If that is not the case then you just have to wing it and use common sense to try and get the best slices. To do what I am doing in this pic with the guide higher on one end to compensate for the taper, you do need a way to adjust the height of your rails and still attach them to the log securely. I use the guide rails that came with my Ripsaw bandmill which make that fairly easy. With home made rails or a ladder, you will have to get a little creative, maybe a movable end piece that slides up or down, something like that. I am sure one of the other milling guys (gals???) that use that type of rail will chime in on that.

Although it doesn't look like as much in the pic below, this log was 42 inches on the butt end, and only 35 on the other, lots of taper. Because I wanted to get some quartersawn figure, I made sure I cut out the taper by doing what I explained above. You can kinda see that in the pic.

nice post and picture

 

[dustytools]

Excellent post Woodshop. I basically do the same thing with a set of rails that I made from some salvaged aluminum storefront window frames, Granberg slabbing rail brackets and a little all-thread. They are adjustable in the width by adjusting the nuts on the all-thread in or out. This allows me to compensate for taper by adjusting the rails wider on the wide end of the log which in-turn will lower it down a bit to make both ends of the rail equal distances from center of the log.View attachment 53023

 

[redoak]

Thanks! I think I was also a little too conservative when I made my first cut, I probably should have taken another inch on the side with too much wain.

Lots to learn.

BTW, I've got a bunch of 10' red oak logs from 12 to 22." I think I recall from this site that one ought to treat the ends to prevent checking? What should I put on them? They've only been doiwn a couple weeks, do you have to wait or just seal them right away?

 

[aggiewoodbutchr]

Thanks! I think I was also a little too conservative when I made my first cut, I probably should have taken another inch on the side with too much wain.

Lots to learn.

BTW, I've got a bunch of 10' red oak logs from 12 to 22." I think I recall from this site that one ought to treat the ends to prevent checking? What should I put on them? They've only been doiwn a couple weeks, do you have to wait or just seal them right away?

It's always better to seal the right away. You probably already have some small checks started in the ends so when you do seal your logs, take care to get those filled too. I use 2-3 coats of left over, mismatched or old latex house paint 95% of the time because it's cheap, usually free. Emulsified wax products such as Anchorseal and others (Bailey's carries their own) do work better with fewer coats but cost $60-$80 per 5 gallon can. That's not an unreasonable price for what you get, but it's still more than free.

 

[woodshop]

Thanks! I think I was also a little too conservative when I made my first cut, I probably should have taken another inch on the side with too much wain.

I tend to be a little too conservative also on smaller logs, not wanting to waste any of the wood. But I'm only fooling myself and spending more time than I would have if I had taken the proper slab off in the first place. On the other hand, if the log is less than 12-14 inches, I often just slice it through and through, no slabbing... and then clean the bark and sapwood off later. More of a pain in the butt, extra work, but you don't waste so much wood. In my case anyway, the quality of a day's milling correlates directly with how much time and care I invest slicing it up. Quick and dirty milling usually gets me quick and dirty (read: not necessarily the best quality) pile of boards.