New sander, or how to sand a large surface?

[Marc Myer]

I have some large 7' tall by 24" wide inch-thick slabs of tree trunk. I took them down to a military base wood shop and went through their safety class for 2 hours, only to be told I couldn't use their big sander.

What's the next step? Buy a handheld belt sander and sweat it out? Use the power of positive thinking? I'm stumped :D .

[Jim Becker]

In lieu of the belt sander, you could use a router-bridge to surface those slabs. Cheap and easy to build and with shimming you can also get relatively parallel surfaces.

[glenn bradley]

Jim's got it. Router sled/bridge. Kinda like this:

http://www.woodmagazine.com/wood/story.jsp?storyid=/templatedata/wood/story/data/408.xml&catref=wd102

[David DeCristoforo]

The router thing would be (for me anyway) a "last resort". I don't know what you mean by "some" but obviously more than two? At any rate, this is going to be a lot of work and the resulting surfaces are still going to need a lot of sanding. Plus, you will have to build the whole setup for something you may not need again. Why not try to find a local shop that has a wide belt sander? They will charge you for sanding your slabs but the result may well be worth it.

[Richard M. Wolfe]

It depends on how much you think you intend to do. For ongoing work a router bridge would be nice. If these slabs are the only thing you think you may do for a good while I'd check local cabinet shops and see if they will do it and get a price. Most have wide belt sanders that would accomodate that size and some may have planers that would do the job.

[Jim Becker]

Aside from the "ease of acquisition" that the router bridge brings to bear, the real reason I recommend it for this kind of job is that most slabs I've worked with and/or seen generally need a bit of flattening to get rid of uneven cutting and drying defects, err...features. Wide belts will surface them nicely, but they will still be as un-flat as they were before sending them through. And the surface left after using a router bridge will be darn nice and in many cases, only require a bit of finishing sanding with a ROS.

[Mike Spanbauer]

Come on now, what better of an excuse for a new tool do you need? Say... a 36" time saver! :) yeah baby!

Seriously though, Jim's router bridge is probably your best bet if you've more than one. Depending on your router (1.5, 2.25, or 3.5 hp) I would suggest going w/ the biggest flattening bit you can find. If you've a 3+ hp unit, you can get a 1" bit (basically, think of end mill for a metal milling machine, which is basically the same dang tool... and cheaper in most cases). This will enable you to clear wood much more quickly and leave as smooth a surface as possible. I would recommend a pair of 1.25x2" square steel tubing, much like a biesmeyer rail. This stuff is tough as nails and doesn't flex. You can build a hardwood / plywood bridge that your router mounts to in order to meet the demands of a specific job, but those rails will last you forever. I've a set myself that have been in use for 5+ years.

You'll have to do some finish surfacing (sanding / scraping) regardless of the method you use to get it flat.

The alternative is to call around and find a shop with a 24"+ jointer / 30" planer. You'll still run a high risk of tearout though on those huge straight knives and it'll be a lot of calling around.

Oh, if you use the router bridge technique, make certain to securely attach the bridge rails to the slab you're working on to ensure that no movement occurs once you begin, or all bets are off for final products reference.

g'luck

mike

[Marc Myer]

thanks for the great ideas! I hadn't thought of the router route;I'll have to take a good look at the slabs and make sure I cut them flat enough!

[Ted Calver]

Marc,
Just curious as to why the military hobby shop would'nt let you use their machine? Were they afraid their might be metal in it?

[David DeCristoforo]

Just one question for you Jim...How nice is "darn nice"? Is that an officially certified level of "niceness"?

[Chuck Saunders]

Why, hand plane and winding sticks :D. Smaller cabinet shops might help you out.

[Marc Myer]

Just a grumpy supervisor. He took a moisture gauge and measured the wood itself, with no moisture present. However, he found a spot of bark still stuck on the outside and managed to get moisture content there. He was just looking for an excuse, and he found it.
I think he knew I work for the Navy--it's an Air Force shop!

[Jim Becker]

Just one question for you Jim...How nice is "darn nice"? Is that an officially certified level of "niceness"?

LOL....with a family forum, some of the adjectives are, well...off limits. :D

[David DeCristoforo]

LOL....with a family forum, some of the adjectives are, well...off limits. :D

Ah, I see. Well I never, ever use those adjectives myself...unless of course I'm working on a computer (which, as everyone knows, is the exception to all rules of good behavour) at which point my family members wisely slip out the back door muttering something about needing ice cream...