Questions about Working Parallam for a Coffee Table

[james glenn]

I am working a design for a coffee table and am thinking about using Parallam as the angled legs in the picture below. The curved wood in the base will be a walnut laminated glue up, and a tempered glass top. A few questions/issues I am having:

1. How hard is it to work with Parallam? Anyone have any experience? I see the Turners use it some for bowls and such.
2. What kind of abuse will it put to saw blades and router bits?
3. Suggestions for connecting the curve to the angled legs? I was thinking about dowels with exposed heads.
4. What is the best way to cut the opening?

I have considered cutting the angled legs in half for assembly, then gluing them back together.

I appreciate the help, as always.

Jimmy

[Jamie Buxton]

What is the best way to cut the opening? Well, it depends on what skills and tools you have. It also depends on how finished an appearance you want.

One approach would be to cut it with a Sawsall. You can buy blades which are longer than the parallam is thick. You'll want to bore a starting hole. The result will be kinda rough; a Sawsall is not a precision tool. But it is quick. There are also folks who cut parallam with a chain saw. But if you're asking here, you probably don't have the saw or the skill to plunge-cut with it.

Another approach would be a plunge router. I'd make a template, and equip the router with a template guide. Most plunge routers don't have enough travel to get all the way through the parallam. So you cut as far as you can go. Then you flip the workpiece over, waste the middle with that sawsall or the like, and then put a long flush-trim router bit in the router -- the kind with a bearing on the tip. The bearing gets guided by the cut you made from the first side of the parallam. Depending on your router, you should be able to cut material that's 3 1/2 or 4" thick. This approach will give you a pretty finished appearance.

[james glenn]

Thanks Jamie. I didn't think about the chainsaw, as it's not very precise. But I could rough it out and then sand/rout it to finish. I am pretty handy with the chainsaw as I grew up logging. Is it hard to sand down? I've worked with LVL before and it's hard to even nail thru.

[Jamie Buxton]

Thanks Jamie. I didn't think about the chainsaw, as it's not very precise. But I could rough it out and then sand/rout it to finish. I am pretty handy with the chainsaw as I grew up logging. Is it hard to sand down? I've worked with LVL before and it's hard to even nail thru.

I've never tried sanding the stuff, but I expect it will be like dry softwood to work. Your experience that it is harder to nail through is probably because you're comparing it to other construction lumber. Almost all construction lumber -- the solid lumber kind, not the manmade kind -- is sold green, so it is pretty easy to put a nail in.

[Tom Scott]

I've never tried sanding the stuff, but I expect it will be like dry softwood to work. Your experience that it is harder to nail through is probably because you're comparing it to other construction lumber. Almost all construction lumber -- the solid lumber kind, not the manmade kind -- is sold green, so it is pretty easy to put a nail in.

Parallams were developed as a structural building element, which is how I know them. I have not worked with them in a furniture application, but expect they would be similar to plywood since they are essentially strands of (soft?) wood held together with a lot of glue.

[Alan Caro]

james glenn,

A couple of thoughts>

1. How hard is it to work with Parallam? Anyone have any experience? I see the Turners use it some for bowls and such.

Parallam is more or less compressed longitudinal chips of fir, pine, and etc. bound by resin and as such is quite hard.

2. What kind of abuse will it put to saw blades and router bits?

I have never used Parallams except in buildings constructed by someone else, but from comments, I assume it would dull tools noticeably faster than solid lumber. I hope that those will direct experience will comment.

3. Suggestions for connecting the curve to the angled legs? I was thinking about dowels with exposed heads.

Because of the modern design, I would suggest drilling holes into the assembly faces, gluing dowels into one side, then gluing and assembling with clamps. The dowels then are never seen. If you wanted to use dowels decoratively, I'd suggest using a contrasting material, letting them protrude- or even painting of staining them a color > actually call attention to them in a "modern", slightly mechanistic style.

4. What is the best way to cut the opening?

In my view, cutting the opening into a huge, solid Parallam would be difficult to do cleanly as the corners would have to done with a reciprocating saw (as opposed to rotary). A router technique is another possibility, but the cuts from alternate sides can't be perfectly aligned and there is again careful neatening up to do. A sawsall is definitely not a precision instrument and unless you can somehow thread a bandsaw blade. In all, I think the results of cutting the opening into a solid piece would take more time to correct and finish than the actuality of the entire legs being cut from a single piece is worth. to achieve the same effect, my suggestion is laminate small shaped sections of the material in parallel to create the cross-members, glue and clamp, clean up the irregularities and alignments, and then attach to the angled legs with hidden dowels > dowels installed in the ends of cross-member that are then glued and clamps into corresponding holes in the interior side of the angles legs. I think you may find that the nature of the material is such that the laminated pieces will have the general "grain" of the chips going in the same direction anyway and will look almost as much a single piece as an actual single piece.

5. I have considered cutting the angled legs in half for assembly, then gluing them back together.

I'm not entirely sure what you mean, unless you mean cutting sections linearly such that reversing one of the pair creates the mirror. which would be a logical way to do it. Again, you might consider using a hidden dowel to join them strongly at the bottom.

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A good project and interesting use of materials!

Alan Caro