flatten ends of 6 x 6 hand-hewn barn beam
wolewyck2
| Posted in General Discussion on
I was gifted a 39″ tall, ~6″ x 6″ hand-hewn beam – probably oak- from a 100+ year old barn. I want to keep it in its original state as much as possible, except that I’d like to get the ends as flat and parallel as I can because I’d like to turn it into a pedestal. It is already pretty stable, standing on end, but I’d like to get it better if possible. I have a shop with intermediate-level tools (contractor style saw, 12″ bandsaw, etc.), but I’ve never worked with a beam before, and I’m not sure how to go about this, or even if I have the right tools to handle the task. How would you approach it? TIA!
Replies
If you have a lathe that will handle 39", mark the centers of the two ends (which is best done with multiple marks, measuring across the 6" dimension and also marking from corner to corner. Take a middle point of all the marks.) You can then turn the ends so that they are perpendicular to the axis you have created. You can turn the bottom end slightly concave for better stability, and the top flat.
Without the lathe, you can make a carriage for the beam that again uses the centers you have marked and your bandsaw (which you have adjusted to cut straight...) The carriage should have a bottom and back, and a strip of wood perpendicular to the carriage that fits in the bandsaw's miter slot. Shim the beam so that the centers at each end are the same distance from both the bottom and back, and trim one end with the bandsaw. Turn the beam around and re-shim it, then trim the second end. You have trimmed each end perpendicular to the center axis, so they should be parallel.
A handsaw? It's only one piece of wood, 2 cuts. A good handsaw with a proper set will cut a straight line and you'll be done in less time than it will take you to think it through and then set up some machine. What's required: one saw , a pencil , a square, saw horses, knee and bicep.
You give the impression that your tools are lighter duty hobbyist type and not well suited to deal with such a heavy piece of wood. Do you own a moderate sized router? If so it would be relatively simple to construct a router sled that could be used to square the ends using a technique similar to what is done when working with live edge slabs. Just be sure to mark your reference face and to square up to the same face for both the top and bottom cuts. If is truly hand hewn its not likely any two faces are exactly square and parallel.
Simply overlap two 3"x 18"x ¾" straight boards leaving an 1" rabbet like ledge make 2 of these. Then drill a ⅜" hole 3½" on either side of center of the 18" length and centered on the 3" width. Using 2 10" long pieces of all thread rod you can now clamp this around the beam squaring it up to your chosen reference face.
The carriage is simply 2 pieces of aluminum angle(aluminum is easily cut with std carbide tipped wood saw blades) ¾" or 1" will work and a length of 12" should be fine but a little longer would not hurt. Screw these to two 3" wide boards with a length adjusted to fit your router base, use 2 countersunk screws on each end to prevent racking, countersunk to permit your router to slide over them. A little wax on the contact surfaces and you should be all set.
I’m a relative novice but if it were me I’d probably go with router jig as esch describes (I don’t have a quality handsaw that’s up to that task. Hmmm….). I was thinking a custom band saw sled might work too. You’d need some way to support or deal with the ~30” of beam that is off the table.
Thank you all. I am a hobbyist and have hobbyist-level tools (no lathe). I think I'm going to try the router jig concept. The beam is long enough to be held upright in my workbench's tail vice, so I can shim it straight and keep it in place with the vice, and then make a router sled that could perhaps be clamped to the workbench top. Wish me luck!
Sometimes a picture helps. It's really a simple concept
That helps a great deal; thank you!
I hope it works. Make sure the top and bottom edges are parallel so you can square things up properly. And again square up from the same two faces.
Consider building the sled to clamp to the beam, you'll be able to pick a referance face on the beam itself. A corner on the clamping part will keep you square (if the beam has a square corner). The top could be just a flat surface with a just-over-beam-sized hole in it. Make a baseplate for the router that spans the hole and you're in business. A 1/2" mortising bit will make a quick job of it.
"Hobbyist-level" tools around here include some ridiculous industrial machines, but we all started with a drill and a box of drywall screws. Good luck with the project!
Okay, so I've made a setup. But now I have a problem with what bit to use. I bought a 1" diameter flattening bit (https://www.amazon.com/gp/product/B09B5ZTYVR/), but the problem is my plunge router (Bosch 1617EVS) can't get the bit far enough below the sled. In fact, the cutting edge does not completely clear the sled, so I will run into the sled itself if I were to use it. I could remake the sled trying the aluminum bracket approach instead of plywood, but I was concerned they might not provide a flat enough reference surface for the router, and that could get translated into the project. Is there some kind of longer-shank bit that might help, or am I missing some other solution? Thanks!
1" aluminum angle is plenty straight enough and would have saved ⅝" of plunge depth.
I have to ask how are you squaring that setup? It looks to have many areas it could get out of square. Clamping directly to the post would have made squaring it a simple task once you picked a reference edge.
Yes, aluminum would have saved some depth, but even so, I was hoping for even a bit more vertical reach with a bit. I ended up going with the Freud 12-172: 1" (Dia.) Double Flute Straight Bit, which has good length and which I think could be useful for future flattening, such as for cutting boards, which I haven't made before in part because of not having a belt sander. But maybe with sled setup and this bit could help me get there, a future project...
To answer your question, I squared the setup with shims-- both between the piece and the tail vise, and underneath the base (not shown) to try to get it as vertical-looking as possible. Shimming under the base wouldn't be needed to cut the second face, once the first face is cut and the piece flipped.
A 1" cutter on a 1/4" shaft is IMO a bad idea. Your router accept a 1/2" collet. I'll say again that a 1/2" mortising bit would be my choice. More passes, less stress on the whole system. 1/2" bit with a 1/2" shaft is rigid and petty ideal. Whiteside bits are a good choice.
I do have a 1/2" collet. I will take a look at the bit you suggest. I was eyeing this one (https://www.amazon.com/gp/product/B00004T7CV/) also, if anyone has reactions to that idea... it is longer overall which might be helpful.
You're trimming a 6x6 beam, that 1.5" bit won't get much use later, a 1/2" mortising bit is something you will find more uses for over time.
Could not agree more. I'd recommend a 1/2" dia by 1" long spiral upcut bit if the budget will allow. There is no need to use a helicopter in this case and the smaller bit gets used all the time.
BTW I bought a 2" long 1/2" spiral upcut thinking I would be able to use it for smaller jobs too - It's far too long and even in a really good router tends to vibrate unless cuts are very light. I ended up buying a shorter bit, which tends to be used for almost everything 1/2" and bigger. the 2" is relegated to really deep mortise work.
Your putting the cart before the horse.
First and foremost you need to design your table. You say the beam is 39" in length. A table ,like a dining table, is going to have a finished height of ( + - ) 30", You have a base and a top to the pedestal plus the thickness of the top to consider to arrive at 30". Depending on your design your going to use closer to half that 39" length for the upright piece than you are maybe considering at this point. Well undoubtedly more than half but you get my point.
So, your still going to have to come up with a way to cross cut your beam.
If I was working on a rough beam like that and wanted to retain the original look I would set the beam upright and find its most verticle TO THE EYE position and from all angles and when I found the most pleasing position I would scribe a verticle line with a level as a reference, probably two -on adjacent sides. Using that line as a reference I would then use a level off of that to find my top and bottom angles. A square off of that line should be perpendicular to a level surface but I would confirm that with a level. There is no quarantee that your beam is perfectly straight or square so your horizontal surfaces might not be right angles to the edges of the beam but you do want them to be perpendicular to a level surface and you want your beam to APPEAR straight up and down or nearly so and for being seen from any angle..
You won't be the first person to have to go back to the drawing board making a jig. A handsaw plus probably a block plane I still think are the perfect tools for this job.
I'm not making a table, I'm making a display pedestal, so I'm okay with the height as it is. Thanks for your input, however!
So, a few responses to various comments here:
(a) I was squaring the setup using shims both between the piece and my vise, and also underneath the piece (not shown). I've used a large square to get it as straight visually as I could. After flipping it for the second side, the bottom did not need shims because I wanted the second side parallel to the first.
(b) I'm not actually making a table but rather a display pedestal, so I'm okay with the height as it is and don't need to crosscut. Thanks for your input, however!
(c) The Freud bit (https://www.amazon.com/gp/product/B0000225W4/) gave me the length I needed and wasn't scary-large diameter, and I can see it being useful in the future for something like flattening a cutting board (since I don't have a belt sander).
(d) Bottom line is-- the setup and bit worked! The top and bottom are flat, and the beam seems pretty vertical, or vertical enough for something that is definitely not square. On to the next steps! Thanks to all! It's fun trying something new.
Just a note to say that I think the sled approach to flatten the ends worked! Many thanks to all!