Which Wood Is Most Suitable?

[sdantonio]

Do a Google search on 'Paralam' and 'Truss Joist'. It is possible these are what are being referred to.

Although if you take the term literally both plywood and MDF could be considered engineered wood.

Engineered lumber includes stuff like using 3 plywood pieces to make up wooden "I" beams. In a sense your doing "engineered lumber" when your making up a tortion box.

[Geof]

Engineered lumber includes stuff like using 3 plywood pieces to make up wooden "I" beams. In a sense your doing "engineered lumber" when your making up a tortion box.

Doesn't sound as fancy from a marketing perspective when you express it this way. When you are converting an almost junk species of wood into a particle board called Aspenite it sounds much better to call it Engineered Wood rather than Chip Board.

[thkoutsidthebox]

Why not just draft up the parts you need and use the old one to cut out parts for the new one?

There is not really any parts on the new router that are too complicated to build by hand, once I take care marking out correctly. The parts that would benefit from more accuracy really require a jointer, as the current router isn't even good enough to surface my boards correctly. But thats a story for my actual new build thread ( Which I'll be posting in the next 48hrs )

I'll look into getting an epoxy to seal everything.
Would a few coats of Yacht Varnish be good enough for this? If not, suggestions are more than welcome.

[thkoutsidthebox]

I should have titled this thread simply: "Which Wood Is Most Suitable". Can we get some sort of list going. By way of effort to start one here we go:

PREFERRED WOOD FOR CNC-ROUTER

1. Baltic Birch Plywood
2. Marine Grade Plywood
3. Hardwood Laminate
   
4. Oak
5. Hard Maple
6. Regular Plywood
7. Other Hardwood
8. Softwood
9. MDF
10. Chipboard

Im shooting from the hip so please change/update it as you see fit.

[sdantonio]

My vote would be 1 or 2. Item 1 probably being the easiest to get a hold of (unless you live along one of the coasts or in a community with some wooden boat enthusiasts around). There probably wouldn't be much advantage in going with 2, and the cost increase would be a negative point also.

Baltic birch is sometimes also refered to as cabinet grade birch ply.

Personally I would stay away from any solid woods due to the dimensional instability with humidity changes (3 & 4). And I would also tend to stay away from 7-10. Although, if you wanted to go wild with item 7, I think it would look very nice (though not very practicle) made from Brazillian Rosewood with maybe an ebony trim

[ger21]

Baltic birch is sometimes also refered to as cabinet grade birch ply.

I wouldn't trust anyone calling it that unless I saw it in person.

2) Similar to above, I'd want a good look at it before I bought it to make sure I knew what I was getting.

3) Not sure what your talking about. Plywood? If so, most hardwood plywood availble today is not very good.

Of these 3, Baltic Birch is the only one I'd use.


I'd use maple before oak, but as I mentioned, I'd rather use a laminated material. Mahogany or walnut are more stable woods, but also more money.

[sdantonio]

I wouldn't trust anyone calling it that unless I saw it in person.

Norm Abram, New Yankee Workshop, uses the term interchangably in both his books and TV shows.

I agree with Gerry. See before you buy. Preferable Baltic Birch.

The only one I would trust sight unseen is the marine ply, and only from a reputable dealer, because it has to pass British Mil Spec BS 1088 which talks about filled voids and filled knots and delamination of the glue.

Laminated maple in preference to oak and I would tend to stay away from red oak. The medulary rays go all the way through making in porous. The boat builders won't use it because it isn't watertight (water will actually flow along the rays which is actually what they are made for anyway). This may cause it to be weaker or less stable than white oak.

[Geof]

You probably have a Table Saw; if not you should have.

Here is an idea from a friend who is a Cabinet Maker; a sanding disc that allows a Table Saw to be used to finish wood strips straight, flat and to a particular thickness. I have not used it myself but I believe my friend when he says it works and it seems reasonable that it would.

First picture shows the disc, in this case machined out of aluminum in the shape of a very shallow cone.

Second picture shows how the disc can be set at the half angle of the cone so the part protruding above the saw table is perpendicular to the surface.

Third picture shows a regular adhesive backed sanding disc with a hole cut in the center and a sector cut out so it matches the cone.

Using this is more or less obvious from the second picture: You adjust the saw spindle to the correct angle, adjust the height so the disc is protruding the needed amount to cover your stock and adjust the rip fence so a single pass through takes off a small amount of wood. You can probably take a pass about 1 to 1.5 mm deep.

You simply take alternate passes of each side of the stock until they are all cleaned up and then finish everything off to the same thickness.

The disc in the pictures is aluminum as I mentioned, I made some for my friend after he had proved the idea with a hand turned plywood disc. With the appropriate amount a care you should be able to make your own disc out of plywood. It simply uses the Table Saw spindle as a wood lathe.

Laminate together four pieces of good 5 or 6 mm ply with the grain crossing at 45 degrees.

Mount this onto the spindle using the normal flanges for a saw blade, clamp a strip of wood across the table at the correct angle as a guide and turn the cone and O.D. Sand, very carefully using sand paper on a piece of wood not just you hands, seal or varnish so the adhesive can stcik and there is your disc.

Now it is possible you need to do a minor and reversible modification to your saw. Depending on the size and style the saw spindle may be running faster than motor speed; the spindle pulley may be about half the size of the motor pulley. This might be a bit fast, as a sanding disc the spindle should be running at around 1200 rpm or so. You can easily calculate what size pulleys to use to get a spindle speed around this.


Once you have your Thickness Sander conversion done you can really start to save money. If you are laminating strips together you do not need to buy full length pieces of wood. Using the Tee square in the guide slot in the table with some strips of wood and clamps you can make a fixture to taper the ends of all your strips on the sander to make scarf joints in the laminating.

Now that you do not need long pieces of wood you are free to scavenge odd lengths from the bins behind woodworking places etc. I suggest you look for old shipping pallets that are being thrown out. Many times the wood on these is really crappy but occasionally you will find some using really hard and heavy tropical woods. I have found this on machine pallets originating from China or Taiwan, the large wooden members in some pallets are very good wood even though the slats might be very punky.

[ger21]

One other thing to keep in mind, is that Baltic Birch (plywood) may be the better for some parts, but hardwood may be better for others. While you could build the whole thing out of hardwood if you wanted, You'd be better of choosing the right material for the particular parts.

[High Seas]

One other thing to keep in mind, is that Baltic Birch (plywood) may be the better for some parts, but hardwood may be better for others. While you could build the whole thing out of hardwood if you wanted, You'd be better of choosing the right material for the particular parts.

Engineered Lumber - I meant the "method" not the specific material -- sorry for the confusion. (but a google will get the idea across)

Ger21 hit the method "right on" - pick the construction method, truss - box, etc. Then, use the material that makes the most sense. Example; most likely you'll use mdf for sacrificial table over "nicer" material, eh?