It’s been a while since I started on this, but was busy with my new job. But the weather forced me back into action.
We’re having an unseasonably warm spring. 8 inches of snow melted in a few days, then rain, and 50°-60° temps. And a huge amount of humidity. I went out in the garage the other day, and was terrified to see the pieces that I ad already glued down loose on the torsion box. The humidity had expanded them so much that they were popping loose, actually tearing the surface of the MDF. And the torsion box was actually getting a slight crown on top. I immediately turned on the furnace, and let it run all week at about 65°, to remove the humidity. After a week, the torsion box flattened back out, at least to within 1/64” or so.
I carefully removed the loose pieces, and glued them back down with some more CA. They had to go back in the same place, because they had spots of MDF attached to them. Keeping them organized was a bit tricky, as I had to re-glue about 50 pieces, maybe more.
Once I had the majority of the loose ones back down, I started work on the rest of the top. I wasn’t too concerned if there were still a few loose ones in the middle, as the epoxy should glue them in place.
When I started before, the “tiles” didn’t fit as well as I’d have liked, because I didn’t really prepare them properly. Rather than have gaps, I carefully fitted any that weren’t tight. This took a tremendous amount of time. This time, I didn’t have time on my side, so I didn’t worry about any gaps. I actually found that it was much easier to split “filler” pieces off the tiles with a chisel, and tap them into place, filling all but the smallest of gaps. So I managed to finish tiling the top in a few hours Saturday and Sunday.
Today, I started to apply the epoxy, to seal out the moisture, and firmly bond the tiles to the top. One thing I noticed was that some how, the two very small drops of CA glue are showing all the way through the 1/8” thick tiles. I used a gel CA, and used very little, so this surprised me. I didn’t see this in the small sample I made. Maybe when I route it flat they won’t be as visible. Anyway, another surprise, was that I put about 1/2 gallon of epoxy on it. And I just checked on it, and it’s all soaked in. It probably would soak in another cup or two. But I’m pretty sure that it’s soaked all the way into the MDF. (I sure hope so)
Here’s a few pics right after I applied the epoxy, a few minutes ago. Tomorrow I’ll flood the bottom of the box with Polyurethane, to seal it up good. Saturday I’ll route it flat, and rabbitt the edges to apply some trim pieces. Maybe bubinga, as I got a bunch from work. When it’s al done, it’ll be coated with several coats of polyurethane, and wet sanded to a glass smooth finish. Can’t wait to finish and start using it.
-- Gerry, http://g-forcecnc.com/jointcam.html