Scribing a desktop into a trapped area?

[Jeff Monson]

I'd like some advice on a good way to scribe a desktop into some built-ins. The desk will sit between 2 built-in chests, so it will need to be scribed on the back and 2 sides. The top for the desk
is 64" x 28.5" deep. I can handle the scribe on the back wall, but I have yet to scribe a trapped top such as this one.

[Andrew Hughes]

I would set a table in the space close to the same height.And make a templet.Start your templet shy of the the sides,add each side separately and scribe.tape or staple them to the substrate for a perfect fit.Transfer the shape to the desk sitting near by.

[John TenEyck]

I've done it by separately scribing a piece of masonite or MDF about 10" wide to the sides and back. Do the back first, then butt the side pieces against it and scribe those. When everything fits perfectly, hot melt glue some gussets at the corners making sure to leave enough room for your router to pass by on the scribed edges.

John

[Mark Bolton]

Have you ever seen the old trick of scribing inlaid (linoleum) into a room? Thats the way I scribe captive tops. If there is no cab below you have to do as andrew suggests and mock up a surface right at the level of the top to be installed. lay out a piece of builders paper (we use red rosin paper a lot). Cut the paper about 1/2" shy of the actual top size and tape it down. You can cut triangle shaped windows in the field of the paper so you dont have to tape edges. Then simply use a straight edge or framing square and butt the square against each side, mark a line on the inner edge of the square on the paper (the edge away from the actual edge of the surface to be scribed). Do this all the way around. Remove the paper, apply it to the top oriented in the location needed. Use the same straight edge aligning with the lines on the paper but now marking a line on the outer edge of the square on the top.

It always still requires a few in-and-outs but it gets you super close.

[Mark Bolton]

P.S. Remember if your opening is closed in the front (rear long dimension is longer than the front dimension) you'll have to back bevel one short edge of the top hard so you can angle it in on the long axis. You of course wont be able to slide it in on the plane its going to reside at.

[Jeff Monson]

Have you ever seen the old trick of scribing inlaid (linoleum) into a room? Thats the way I scribe captive tops. If there is no cab below you have to do as andrew suggests and mock up a surface right at the level of the top to be installed. lay out a piece of builders paper (we use red rosin paper a lot). Cut the paper about 1/2" shy of the actual top size and tape it down. You can cut triangle shaped windows in the field of the paper so you dont have to tape edges. Then simply use a straight edge or framing square and butt the square against each side, mark a line on the inner edge of the square on the paper (the edge away from the actual edge of the surface to be scribed). Do this all the way around. Remove the paper, apply it to the top oriented in the location needed. Use the same straight edge aligning with the lines on the paper but now marking a line on the outer edge of the square on the top.

It always still requires a few in-and-outs but it gets you super close.

Makes perfect sense Mark, thanks for the tip.

[Keith Bohn]

You can use the same method as templating for a solid surface top with strips of luan and a hot melt glue gun.


http://www.replacementcounters.com/blog/image.axd?picture=2010%2F6%2FMossCorianTemplate.JP G

From there you can transfer the outline to your top and cut to the fat side of the pencil line and finesse the final fit with a belt sander.

[Mark Bolton]

You can use the same method as templating for a solid surface top with strips of luan and a hot melt glue gun.
From there you can transfer the outline to your top and cut to the fat side of the pencil line and finesse the final fit with a belt sander.

We use this method almost exclusively to send templates to our top fabricators. We mark each piece, screw them together on site, disassemble, bag the screws, ship it off to the top shop. The only thing I find is when fitting a smaller top where your trying to conform to very small/shallow wall defects the long strips just dont allow for that kind of detail. Luan templates work great for larger tops like the one in your image which will be caulked/grouted-in.

I have at times used the paper template with a top captive on 4 sides (one side is in a cove) and have cut a small 6" block of wood to transfer the opening out to the paper template. The small block allows you to transfer very minor bows/bulges in the wall to the template. The accuracy all depends on how far out the space is. If its really bad a small block makes fitting harder. Ive tried it using scribes but I always seem to do better with some sort of straight edge. I think it averages out the defects a bit and doesnt rely on you keeping your scribes at a dead right angle to the face they're riding against.

Four sides captive is a a real patience tester!

[Peter Quinn]

The only thing I find is when fitting a smaller top where your trying to conform to very small/shallow wall defects the long strips just dont allow for that kind of detail.

I like the rosin paper idea a lot, I have an install coming up on which I'm going to try that one! I've used the luan templates with good success by actually scribing the individual pieces for a glove like fit, them gluing it up, then transferring the whole thing to the work piece. For small things I've done two solid pieces of 1/4" mdf with a break in the middle and a few strips to bridge the gap, scribe each side independent, works like a dream.

[Dave Zellers]

The rosin paper transfer method was the single most important technique I learned as a ute in the carpentry trade 40 years ago. But vinyl flooring is a lot more forgiving than wood. If the sides you are scribing to are straight, you can use a longer straight edge, if they are curved at all, a shorter straight edge will be more accurate. Another trick is to slightly back cut and stay off the line by 1/32 or so and then use a block plane or file or even a sandpaper block to fine tune as you test the fit.

[Keith Bohn]

Fine Homebuilding ran a tip a couple of decades ago showing how to use tick sticks. These also go by tickle sticks and joggle sticks.

If you Google those you can get a clearer idea than any description I can muster.

[Dave Zellers]

The luan / glue gun method would give a perfect fit as long as you took the time to scribe each piece to the wall before gluing.

[Dave Zellers]

The luan / glue gun method would give a perfect fit as long as you took the time to scribe each piece to the wall before gluing.
And in thinking about it further, I would put the 3 scribed sides in the same plane (sitting on the same surface and not overlaping) and then glue corner blocks to the top.

Plus I would have to appease my 'anything can go wrong' fears and glue on a diagonal before transport to the shop.

THAT would provide a perfect pattern.

[Dave Zellers]

Fine Homebuilding ran a tip a couple of decades ago showing how to use tick sticks. These also go by tickle sticks and joggle sticks.

If you Google those you can get a clearer idea than any description I can muster.

WOW, I did not know about this method. What a simple yet accurate system. The more points you input, the more accurate the result, yet it's all done with a very simple stick.

If I was using this method with a lot of reference points, I would alternate using even numbers and odd numbers for each reference line to avoid confusion.

Thanks- this is awesome.

[Larry Edgerton]

I use the template method Keith shows with the exception of using 1/4 tempered Masonite, and I usually screw on a couple of diagonal corner braces. I like the Masonite as I can roll the whole thing up into a big circle and throw it in the back of the truck to take to the shop in one piece.

[Jim Matthews]

Okay, that's clever.

Hot melt gun makes fitting the field easy enough.
It's sufficiently durable to transfer to the final material.

Consider this idea stolen (*ahem*) borrowed.

[Jim Matthews]

That's the way I've been taught.

I get better results, using just one stick.
If you use more than one - make certain that they're easily identified.

If they're close to the same dimension, confusing them will induce errors.
DAMHIKT

260545

[Larry Fox]

+1 on the template idea. I always build one whenever I need to scribe anything into a particular spot. MDF is just too cheap to risk it with a finished product.