Page 1 of 2 12 LastLast
Results 1 to 15 of 29

Thread: Prepping and laminating lumber for a benchtop

  1. #1
    Join Date
    Feb 2021
    Location
    Israel
    Posts
    59

    Prepping and laminating lumber for a benchtop

    Hi everyone,

    I want to start by thanking everyone for being so helpful so far, for such a new member I have been definitely been taking advantage of this forum. as someone who lives in a non woodworker friendly country, this forum has been an incredible resource.

    OK here it goes:

    I am going to build a split Roubo benchtop 4" thick (or more, depending on what I can get out of the stock) and 62" long (small space).

    At my disposal are the following tools: LN 62 LA jack, LN no.7 jointer, LN no. 4, and a 1980' Stanley 4 1/2 that I am tinkering around with. I have a rough panel saw, and a circular saw and a router (the kind that doesn't belong on a Neanderthal thread ).

    the stock is hard maple, kiln dried 2" thick by 5.9" (15cm) which I can get to a max length of 3.5 meters/ 137"/11.4', and minimum length of 3meters/118"/9.8'

    here are my questions:

    1) considering I am going to choose the boards myself, what a is a reasonable yield per a board? how badly am I deluding myself by thinking that a 137" board can supply 2 62" boards for the laminate? What about one 62" board and one 32" for the legs? how would you approach maximizing the useful lumber?

    2) the glue up: my approach right now is to edge joint one side, plane the faces flat, and then glue and clamp them in face lamination. I thought of using cauls with 1" wedges in the top as necessary to push boards of uneven height down and maintain a relatively flat edge on the jointed side. I will have some extra helping hands for this. once I have the 2 laminated slabs I figured I would plane the uneven side and thickness the two slabs roughly even. I am concerned about how long planing the boards will take me. I don't want to finish the boards, get ready for a glue up and find out that they have twisted or warped and need to be planed again.
    - Any Idea how to prevent or minimize this?
    - Is the caul and wedge thing feasible? I came up with it on my own, and have no idea if it will work
    - how many clamps should I get for a 62" lamination (62" x 12" x ~4 1/2")?

    it should be noted that this is my first hand plane project and I do plan to practice on scrap first but still, I don't expect amazing results from myself as a newbie.

    Thanks a lot
    Assaf

  2. #2
    Join Date
    Dec 2010
    Location
    South Coastal Massachusetts
    Posts
    6,746
    It's been done. Consider contacting members that have (recently) posted about it.

    https://sawmillcreek.org/showthread....+a+robot+bench

  3. #3
    I am not sure where you are getting your hard maple, but I would not recommend hard maple from eastern North America. We have two related species that are put in the hard maple category, Acer saccarum, and Acer nigrum. They can have sections that are hard to plane and are rough on plane irons, actually worse than timbers that are significantly harder. In historic times woodworkers often made tables with hard maple legs and tops of another species.

    Hard maple is also very poor at absorbing shock. Woods that deaden shock are better for a bench where you are mortising and such. Beech, ash and soft maple are much better in this regard.

  4. #4
    Join Date
    Feb 2021
    Location
    Israel
    Posts
    59
    I wish I had the luxury of choosing where my wood comes from. last time I went to the lumber yard, the sales associate couldn't tell me if they had anything quartersawn or what quartersawn was for that matter!

    Israel is an Ikea empire

  5. #5
    Join Date
    Feb 2021
    Location
    Israel
    Posts
    59
    Quote Originally Posted by Jim Matthews View Post
    It's been done. Consider contacting members that have (recently) posted about it.

    https://sawmillcreek.org/showthread....+a+robot+bench
    Ive already looked at every benchbuilding blog and post I could get my hands on, as well as joined the woodwhisperer guild. my questions are primarily about the approach to taking rough lumber to laminated slab. I couldn't find anything on that (I admit I may have missed something). also the OP of the post has done a really nice job, but I believe he used at least some power tools?

    thanks
    A

  6. #6
    I agree US native hard maple can be hard to plane/subject to tear out & for this reason, before you glue up, make sure all the boards have the same grain direction, or you'll be in for a mess when hand planing. Try to avoid boards that look like they have figure or wavy grain patterns.

    I would not wedge anything down, you're working against the stress forces in the wood. Just let the edges go where they want and flatten later.

    If you have a router, I would strongly recommend a router flattening jig.

    A 4" thick maple top is going to be very strong.

  7. #7
    Join Date
    Mar 2020
    Location
    Central TX
    Posts
    21
    Hey Assaf, congrats on embarking on your bench build! Here are a few lessons I've learned from building pieces that are based on large face laminations. Take them for what they're worth, and there are lots of good tips already in this thread as well. And, if you haven't yet, you may check out The Anarchist's Workbench from Lost Art Press. The pdf of the book is free, and even though your design isn't the same it has a lot info that applies to designs that use face laminations.

    It's hard to say how much yield you can get from your lumber without seeing it. However, with face laminations remember that the faces can have defects (within reason) because the faces will be glued together, which will stabilize and hide the defects. So as long as the defects don't extend to the edges, you're good. For the bench top, I honestly just look for one clean edge; you put the other edge with defects on the bottom. Considering this, I bet you can get pretty long boards out of your rough stock. You really only need two boards with a clean face for the outsides of each lamination.

    Getting bow and twist completely out of the length of long boards can be somewhat challenging. If you can get them "pretty good" (but not necessarily perfect), your clamps will pull them straight during the glue up. Same goes for if they move after planing. If it's just a little, don't worry about it and strong-arm them with the clamps. Doing a dry run with the clamps to see if they can pull the gaps closed will show you if you need to do more work or not.

    Orienting the boards with matching grain direction if possible is a good suggestion as it'll make flattening the top easier. If it's not possible and/or the top is giving you fits with hand planes, you could rig up flattening jig for your router as was recommended previously.

    I wouldn't worry too much about getting the edges aligned perfectly with cauls. If you've got everything reasonably straight with your No. 7 and your clamps are sitting in the same plane, putting the jointed edges facing down on the clamps should make that side come out reasonably flat without cauls. It'll probably be easier to flatten any slight misalignments afterwards than potentially chasing your tail during the glue-up with a caul system. Hard to say for sure though without seeing the prepped lumber and your clamp set up.

    As for the number of clamps, as many as you can get your hands on of course . I find with thick laminations it helps to have clamps along the top and bottom (as opposed to just a single row of parallel clamps). 3/4" pipe clamps would work well, maybe 6-8 on each side? You might start with four or five on each side, then add additional clamps where there are gaps.

    Hope that helps, and good luck!
    Last edited by Daniel Culotta; 03-01-2021 at 12:33 PM.

  8. #8
    Join Date
    Feb 2021
    Location
    Israel
    Posts
    59
    Quote Originally Posted by Daniel Culotta View Post
    Hey Assaf, congrats on embarking on your bench build! Here are a few lessons I've learned from building pieces that are based on large face laminations. Take them for what they're worth, and there are lots of good tips already in this thread as well. And, if you haven't yet, you may check out The Anarchist's Workbench from Lost Art Press. The pdf of the book is free, and even though your design isn't the same it has a lot info that applies to designs that use face laminations.

    It's hard to say how much yield you can get from your lumber without seeing it. However, with face laminations remember that the faces can have defects (within reason) because the faces will be glued together, which will stabilize and hide the defects. So as long as the defects don't extend to the edges, you're good. For the bench top, I honestly just look for one clean edge; you put the other edge with defects on the bottom. Considering this, I bet you can get pretty long boards out of your rough stock. You really only need two boards with a clean face for the outsides of each lamination.

    Getting bow and twist completely out of the length of long boards can be somewhat challenging. If you can get them "pretty good" (but not necessarily perfect), your clamps will pull them straight during the glue up. Same goes for if they move after planing. If it's just a little, don't worry about it and strong-arm them with the clamps. Doing a dry run with the clamps to see if they can pull the gaps closed will show you if you need to do more work or not.

    Orienting the boards with matching grain direction if possible is a good suggestion as it'll make flattening the top easier. If it's not possible and/or the top is giving you fits with hand planes, you could rig up flattening jig for your router as was recommended previously.

    I wouldn't worry too much about getting the edges aligned perfectly with cauls. If you've got everything reasonably straight with your No. 7 and your clamps are sitting in the same plane, putting the jointed edges facing down on the clamps should make that side come out reasonably flat without cauls. It'll probably be easier to flatten any slight misalignments afterwards than potentially chasing your tail during the glue-up with a caul system. Hard to say for sure though without seeing the prepped lumber and your clamp set up.

    As for the number of clamps, as many as you can get your hands on of course . I find with thick laminations it helps to have clamps along the top and bottom (as opposed to just a single row of parallel clamps). 3/4" pipe clamps would work well, maybe 6-8 on each side? You might start with four or five on each side, then add additional clamps where there are gaps.

    Hope that helps, and good luck!

    very helpful, except I need to start saving for more clamps! :P

  9. #9
    Join Date
    Feb 2021
    Location
    Israel
    Posts
    59
    I was planing on flattening it with a router jig. I already planned on checking grain direction, I don't think I can check that on a rough sawn board before I buy it, or is there some sort of wichcraft I'm unaware of?

  10. #10
    Hi Assaf. I'm pretty new to this myself, but I just finished a couple of workbench top laminations (out of 8/4 ash) so hopefully I can add a bit to the already great advice you've received. Daniel has already summarized a lot of what I found helpful.

    Understanding ahead of time that it's difficult to remove all of the bow and twist out of such long boards is helpful. As Daniel suggests, getting them close and then doing dry fits with clamps to see if you can clamp out any minor gaps should work. Doing your laminations in smaller batches can also help with getting sufficient clamping pressure. I'd also be generous with the glue! Smaller batches could also help you to address your concern about getting the boards clamped up soon after you've dimensioned them.

    As far as the time it takes to flatten the full top, it's really not too bad. If you can set up one of your planes for rough removal, that'll speed things up. I have a dedicated scrub plane, but I have also used my LN LA Jack to hog off material (just with the mouth opened up and the blade set for a deep cut). They sell a toothed blade for this, but I found it did just fine with the standard blade.

  11. #11
    Join Date
    Feb 2021
    Location
    Israel
    Posts
    59
    Quote Originally Posted by Dan Grano View Post
    Hi Assaf. I'm pretty new to this myself, but I just finished a couple of workbench top laminations (out of 8/4 ash) so hopefully I can add a bit to the already great advice you've received. Daniel has already summarized a lot of what I found helpful.

    Understanding ahead of time that it's difficult to remove all of the bow and twist out of such long boards is helpful. As Daniel suggests, getting them close and then doing dry fits with clamps to see if you can clamp out any minor gaps should work. Doing your laminations in smaller batches can also help with getting sufficient clamping pressure. I'd also be generous with the glue! Smaller batches could also help you to address your concern about getting the boards clamped up soon after you've dimensioned them.

    As far as the time it takes to flatten the full top, it's really not too bad. If you can set up one of your planes for rough removal, that'll speed things up. I have a dedicated scrub plane, but I have also used my LN LA Jack to hog off material (just with the mouth opened up and the blade set for a deep cut). They sell a toothed blade for this, but I found it did just fine with the standard blade.

    thanks, I think I am begining to feel confident about my build plan - I know about the toothing blade. I ordered the LA jack this week (waited until pay day) and the toothing blade is now sold out and they don't know when it will be back. so it goes. Glad to know you can hog off material with the LA jack though.

  12. #12
    Join Date
    Oct 2004
    Location
    SoCal
    Posts
    767
    My suggestions:

    Read the Anarchist's Workbench (mentioned above)

    * Orient the top edge grain so that it all runs the same way

    * Pick the piece that you want for the bench front (fewest defects) and mark it

    * Glue up in pairs. Then glue the pairs together - repeat until done.

    * As long as you glue them in the center you can join two shorter pieces end to end - the glue will hold.
    * Put two pieces of angle iron at each end of the boards to be glued so they form a point ^ Put the top edge down on the angle irons. If you boards are straight to begin with then they will be when the glue dries. It will make flattening easier.

    Pick your glue carefully. Note that TB III gets soft @ 150F

    Trying to prep all that lumber by hand will be a journey for a neophyte with hand planes. I wish good luck.

  13. #13
    Join Date
    Feb 2021
    Location
    Israel
    Posts
    59
    Thank you

    I've read the anarchists workbench. great book and really helpful.
    what glue would you suggest using? I was actually hoping for TBIII for the extended work time.

  14. #14
    Join Date
    Feb 2021
    Location
    Israel
    Posts
    59
    OK i looked into it, I can get Titebond II, but not Titebond II extend, do you think that could work? Id be working on laminating a couple of boards at a time...

  15. #15
    I imagine Titebond II should work just fine, especially since you're laminating just a couple boards at a time. If the glue starts to tack up a bit and you need to make smaller adjustments, you can back off of the clamping pressure and make hard taps with a rubber mallet or wooden mallet to persuade the boards into place.

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •