In case you didn't catch my witty title, this round is going to be all about pressure...or in this case all about the glue up on the workbench slabs. I have to admit that this task was fairly stressful on top of it all; which makes the title even more relevant...
After sorting through the pile of boards and reassessing them for grain direction, bow/cup/crown etc one last time I had my slabs roughed and ready for some glue.
Due to the number and sizing of clamps in my collection I knew that I was going to have to tackle this process in two lumps over different days. In hindsight I wish I had thought my processes through a tad more rather than jumping in all gonzo, but hey...that's me and that's my woodworking style. Due to the smaller number of pieces I opted to run with gluing up the front slab first. In the days leading up to this point I had very good intentions of stopping and picking up a small foam paint roller to aid in my application of glue, but alas my brains must have been clouded with too many malted hops because I totally forgot. No worries, it'll work out with just my squeeze bottle of glue and my glue roller....right? Weeeeell.....mostly as you'll see in a few moments.
In an effort to assist with aligning a stack of 5 heavy slippery boards I opted to install a few #20 biscuits in each piece. In retrospect I wish I had placed one about every foot or so rather than the every 18-20" than I did. I also placed these from the bottom of the slab as deeply as my plate joiner would allow (about 1.5"). Can I say that I was and still am fairly jealous of those guys out there that have a Festool Domino at their disposal because it would have made this process that much sweeter and my alignment that much better. But even with my #20 biscuits the alignment and process wasn't too bad and I'm actually pretty happy with the overall end result.
In my experience biscuits work better if they're glued in place so I made sure that each pocket received a squeeze of glue directly before inserting the biscuit and capping it all off with the next board. I don't have any scientific evidence of it but to me the extra exposure to glue directly in the pocket causes the compressed beech to expand that much quicker and makes the alignment of the pieces that much better. I could be totally off base here...and if I am...oh well.
So after what felt like an eternity and a TON of glue it came time to apply some pressure....as in the 8 or so parallel clamps at my disposal and a few F clamps from my rack. The problem I ran into is that as I was rolling the glue my little glue roller just took too much time. Overall the process took about 18 minutes and I thought I was rushing through. For those of you not in the know that is damn near if not over the limit for the open time on basic titebond.Thankfully I had cooler temperatures on my side which pushed the open time back a bit and just may have saved my butt.
I also think I had a few different factors in play during this time. 1: the amount of time it took to do the glue up, 2: the amount of glue and 3: not enough clamping pressure. Add all of these factors together and what have you got? A mess...well not too bad, but it could have been really bad. Thankfully the extra length I added into my pieces saved my butt and I mean SAVED my butt. After I pulled the clamps I found a few pieces that hadn't laminated nice and tight, resulting in a hairline gap. But these gaps were only at the very end of one end and due to my extra length it gave me just enough to chop this piece out and move on.
After realizing my potential faults during the front slab I made sure I wasn't going to have a repeat on the rear slab. I picked up a 4" foam paint roller to do my spreading and man am I glad I did. The amount of time it took to glue up the rear was only 12 minutes and that's with an extra 2 boards in the mix. This time around I wasn't taking any chances on clamping pressure and pulled out all the stops. With the extra few boards in the mix I didn't want to give the slab any opportunity to move.
At the end of the day I was fairly happy with the end results. Each slab was fairly flat with minimal slippage on each piece. Each slab did have a board or two that had bowed a tad or slipped a bit during the glue up but a few passes with my #7 jointer and things were ready to run through the planer again.
Did I mention before that the slabs were big? Cause they're EFFING HUGE now...If it wasn't for the wife giving me some support (emotional and physical) I don't think I would have gotten each slab through the planer...at least not without blowing a gasket lifting each one for a few passes through it. After it was all said and done my final slab thickness at this point is 4-5/8".
Up next is the front slab tenon, screw cavity and end cap...if I'm lucky
Total Build Time:
- 1.5 hours (lumber selection, transport & stacking)
-4 hours (Top Slab milling)
- 1.5 hours (slab prep and glue up*)
-0.5 hours (preliminary flattening of both slabs)
-0.5 hours (Final rough slab milling)
-8 hours total
*I haven't included my clamp time in these figures if you want to add those figures in, each slab sat for 24 hours taking the entire process to 56 hours with down time.