building my own longboard deck press: part 3

In part 1 and part 2 of this sawdust laden saga, I built a press using fence timbers and a pair of hydraulic jacks. I named it Monster Clamp and got one good pressing out of it after many, many failures using different molds I made. Eventually what saved the project wasn’t the press, it was the mold. In part 2 I mention that I had one made and shipped to me from Oregon.

What I didn’t mention in part 2 is that the deck pictured there was the last one Monster Clamp would ever press.  At some point during the pressing process, the new board lay inside the mold all cozy and warm while the glue was setting when suddenly a loud bang accompanied by a dust cloud filled my senses. I went over to the press only to find that it had popped. Bent bolts, splintered wood, dust everywhere, and my work in ruins, I cracked open a beer and said “well, shit.”

I did the only thing a red blooded American man would do in this situation. I sat down and designed a better one on the back of a scrap piece of paper. Shortly after that i was at Lowes filling my cart with more wood, bolts, screws, nuts, and washers.

That’s 16 8ft 2×8’s stacked up in my cart, along with 16 carriage bolts with washers and nuts to match, and about 100 wood screws. Did you know they don’t open until 8am on Sundays? Is that because of this religious freedom I keep hearing about? I was there at 7am but I was forced to go home for over half an hour before I could go back. Rather than waste all that time doing something meaningless, I sat out back by the hot tub and enjoyed the morning air.

Finally I got home and was able to unload all of this wood while my Chief Trials & Engineering Inspector helped clear the way. He’s a stickler for keeping things just so, and clearly this ice chest was in the wrong place.

Once all the unloading was done, it was time to measure and cut everything. My design called for a very simple laminated structure. That means there were a lot of pieces, but only four different lengths to work with and all of them could be cut from the 2×8’s. This probably would have taken less time if I had a bigger chop saw, but I’ve become rather good at flipping the boards over and lining up the cuts perfectly to cut all the way through without having an uneven cut. Most of them you can’t tell at all that I even did that.

Finally the pieces are all cut and stacked up ready to go. Now the laminating begins.

I used a slightly different pattern between the layers when laminating. I used two different patterns and alternated them with each layer. In one pattern, the sides go all the way to top, while in the second pattern, the top goes all the way to the ends. This way the corners are dovetailed giving the joints a lot more strength than before. Between each layer, I rolled on a thick layer of wood glue, then screwed the pieces down to the pieces below it.

That process was repeated over eight layers, giving me a press that’s 12″ wide, 63″ long, and 48″ high. As you can see below, this thing is full of screws and glue. Its already very, very strong just as it is, but I decided I wanted a little reinforcement at the joints as well as in the two pressing surfaces: the top and bottom.

The carriage bolts fit the bill nicely. I added tow in each corner, and four across the top and two across the bottom to keep things strong and tight while the jacks are pressing the mold. The bolts help keep the load distributed across all of the boards (the glue and screws do this too, of course).

Once the bolts were in, the sanding began. I had the sand the inside bottom as flat as possible because that’s where the mold rests. An uneven surface would place uneven pressure on the mold and could potentially cause the mold to split. That’s the last thing you want here. After sanding it flat, i also added a smoothly sanded sheet of 1″ cabinet-grade plywood to absorb any leftover unevenness in my sanding job as well as create a gapless surface on which i can slide the mold into place.

On the top of the inside, I added a pair of 4″x4″ blocks with steel plates on the bottom to distrubite the load from the very small jack heads across the width of the press. Simply putting the jacks in there against the bare surface of the press itself would result in a huge divot, and possibly even splitting and cracking of the press.  The base of the jacks is much wider, so just using a couple pieces of scrap wood to diffuse the load onto the top of the mold will do just fine.

So that’s it for the press. Some additional modifications I have made include pinning the mold for center lines. Below you can see what i did.

I measured for center in the female side of the mold. I drilled two tiny holes at each end of the mold just deep enough to drop one of those crappy little finishing nails into it while leaving just the point poking out. In the above picture, you can see the nail in the mold while the epoxy i used to glue it in is drying.

That nail was way too sharp to be useful, so once the epoxy cured, i dulled it down to a nice little bump that would barely even scratch the veneer, much less leave a bunch of false centers. The venner just slides across the dull nail with no issue, and doesn’t leave a mark at all until it is placed in the press and the jacks come down on the mold with most of their alledged four tons of pressure. Below you can see an uncut blank fresh out of the press with the little divots on it.

 

Those little divots save a lot of time. There is no more guessing at all about where the centerline should be. This is important because you cannot rely on the veneer’s edges to tell you where the shape center is. The veneer is varying widths. You also can’t reliably trace the edges of the mold with a pencil while the veneer is being pressed in because of the visqueen sheeting used to keep the veneer (and its glue) isolated from the mold.

If all goes well, those divots will tell you exactly where to place your template so you can trace out your shape and start cutting.

So far this has worked out very well for me. I’m now able to press, cut, and sand very consistent decks and plan on using this mold for a few different cutout shapes. The one pictured above is called Scarlet and will be featured in its own deck design post coming soon, and will also be available for sale in the shop.


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