Making curved layout edges - methods and suggestions please...

K.b.,

Tom Tee is one of several go-to guys for curved benchwork.

See some of his handiwork here: https://ogrforum.com/...43#83086529522029343

Mike

Tom Tee is a true benchwork craftsman.

Check out L-girder benchwork, also.

Here is a model I made to demonstrate the L-girder method for a workshop I did at York many years ago.

You have total control of the shape of the layout edges with this method. By varying the lengths of the joists, you can achieve any shape you want.

Any good benchwork book will include the construction details. A Google search will also bring up many websites on the L-girder construction method.

Tom is responsible for me going from my planned rectangular layout to this.   He's the go-to man if you want to know how to do a curved layout.

GJ - that smooth curve is what I like,  any idea what material was used?  Looks like 1/4” by 6” lauan plywood, perhaps ripped from a 4’ x 8’ sheet.   I like it but wonder how to hide the plywood laminations along the exposed top edge.

I’ve done L-girder benchwork before but it seems like making smooth curves would require many precision cut supporting pieces.

Has anyone tried bending MDF baseboard?  I made a routed slot car track which had a “Laguna Seca” style downhill curve.  I did that by making shallow cuts cutting on the underside of the MDF and then bending.  Relief cuts?

This is good stuff and you wood workers are an impressive bunch.

Jay

This is the underside of one of the layouts I had made. I used 2 layers of 1/8" hardboard (hardboard tempered panel).

It is a denser version of MDF, but flexible. The 4" strips were glued to edging and pinned with brads and micro pins. Small plywood blocks were added for additional support, especially at joints. The second layer was glued to first. Butt joints were clamped, to make sure they stay and not lift. Try not to have joints in a tight radius location. The top edge was skimmed with wood filler and painted.

You can also get a product called wiggle wood or bending plywood. It works well but the face can be grainy and need a bit of prep. In my case the hardboard was cheaper.

Here's a link to where the layout saga starts:  Putting the top on the GRJ Layout.  I've posted a few shots from the build below, but you can check that thread for the whole tale.

The basic steps were to install the plywood and join all the sheets and secure it to the benchwork framework.  As you can see, I used 5x5 Baltic Birch sheets and they were joined between the beams into one continuous large surface.

Once all the plywood was in place and secured, then the edge profile was cut, that's where the curves were initially determined.  The pegs were to keep all the sheets exactly aligned before they were stapled down with several thousand power staples.

Next came the support blocks for the first layer of fascia.  The blocks butt against the benchwork supports and are cut to conform to the curved shape.  They're screwed, glued, and clamped into place using construction adhesive. When that dries, they're permanent.

The blocks are then covered with 3/8" 3-ply Lauan plywood, the really bendable stuff, Tom calls it "wiggle wood".    It's formed to the curved shape desired, and any bumps in the curves are smoothed by simply pulling the Lauan into the "perfect" curve.  The adhesive used allows really large gaps and it dries into an immovable object!  The first fascia layer is the top piece in the shot below.

The support blocks are generously covered with the Loctite PL3 adhesive, and the first layer of fascia is applied.  Hopefully, the canvas catches any drips of adhesive, once it dries, it's a permanent part of anything it's attached to.

Here you see the gaps I spoke of, this varied as adjustments were made to get a smooth curve on this layer of fascia.  Since this will determine the flow of the curves on the finished product, any adjustments need to be made now.

Next is the Homasote, any straight cuts were done with a utility knife to minimize the mess.

Curves were cut with a jigsaw with a metal cutting blade, and the vacuum was always nearby to get most of the dust.  The Homasote was secured using 1" coarse drywall screws.

Once the first layer of fascia is on, the Homasote is laid, and the edges are routed to exactly match the curves of the fascia layer.

Final shaping and clean-up of the first fascia layer with the Homasote surface.

Homasote installed, screw heads covered, and sanded out.  Well, mostly covered still have to get to a few of them.

Homasote filled, painted to seal it, ready for the next step.

Second layer of fascia getting adhesive to secure it to the bottom layer.

A flexible board is placed on top of the second Fascia layer to keep it firmly in contact with the bottom layer and it's all clamped with spring clamps.

A LOT of spring clamps!

That's all it took to end up with this.

OK, OK, there were a few steps!

That looks great!

Thanks for sharing your pictures with explanations.

I just got several ideas from your post.

Richard

Awesome description with pictures, thank you John, one question please. You stated

Once all the plywood was in place and secured, then the edge profile was cut, that's where the curves were initially determined.  The pegs were to keep all the sheets exactly aligned before they were stapled down with several thousand power staples.

Did you staple the plywood directly to the Mianne Benchwork braces using a power staple? How does that go through 1/2 or 3/8 inch plywood? Or were you referring to something else?

Last, does Tom provide plans or work on design or ?

Thank you,

Paul

John,

Looks like a cabinet maker did that. Is that your background? Very impressive

Jay

@Railrunnin posted:

Awesome description with pictures, thank you John, one question please. You stated

Once all the plywood was in place and secured, then the edge profile was cut, that's where the curves were initially determined.  The pegs were to keep all the sheets exactly aligned before they were stapled down with several thousand power staples.

Did you staple the plywood directly to the Mianne Benchwork braces using a power staple? How does that go through 1/2 or 3/8 inch plywood? Or were you referring to something else?

Yep, we stapled with #18 staples directly into the Mianne I-beams.  We sacrificed a couple of spares shooting them with staples to see if it would be a problem first, and decided it was not an issue, no splits or issues.

You'd be amazed what enough air pressure will do driving staples into wood.   I'm pretty sure you can drive the 1" staples into solid oak with the air stapler with no problem.  I regularly shoot #18 nails into maple furniture gluing tables and chairs back together, furniture gets hard use at my place.   The staples went through the 1/2" Baltic Birch into the I-beams and were properly countersunk slightly below the plywood surface.

@Railrunnin posted:

Last, does Tom provide plans or work on design or ?

No plan, I already had the Mianne benchwork setup, and Tom arrived in a nick of time to make the layout the magnificent beast it is as opposed to the plain table I had originally envisioned.

@Tranquil Hollow RR posted:

John,

Looks like a cabinet maker did that. Is that your background? Very impressive

Jay

A cabinet maker did to most of it, it just wasn't me!   I was the guy holding the tools for a lot of this job.  I did learn a lot, and I actually did do some of the finish work, that was after expert tutoring.

Thank you John, looks like a staple gun is in my future as my plans are Mianne,, plywood, homasote and then roadbed.

How did you countersink the staples? A wide wedge with a mallet? I guess it doesn't have to be too pretty since the homasote is going over the plywood that is stapled to the framework.

Paul

Thanks for the pictorial GJ - gives me everything!  Homasote is special order here in PNW.  I used baltic birch recently - nice stuff, smooth surface and dense.

The staple gun does that for you, just point and shoot.   You could hardly see the stapled places.  Of course you have to carefully map out where the I-beams are so you can hit them with the staples...

Here are a few pics of our layout.  At one end is a 7ft curve with a mountain built into it. We used 1/8 hardi board to bend around corners. With a combination of liquid nails, and specialty lag it keeps the edging in place.  I painted the edging red to help accent the layout and room. Kinda a industrial look. The mountain is almost complete now, these photos are from August. 

I'm having good success using 5mm subfloor ply from H.D.  (a non-layout project).  I thought I would have to order 3mm bending plywood (Columbia products special order from the H.D. contractor's desk) but the subfloor stuff is inexpensive and is working well so far.   Same technique as GRJ's project using butt blocks to define the curve, but I use Tightbond glue to bond multiple layers of ply.  End result is curved plywood.   For these projects, one can never have too many clamps.

So far, I have not found voids (that will kink the bend) in the 5mm subfloor ply when I cut the 4" strips.  The stuff wants to bend, and I doubt I would be happy with it to form a flat subfloor.

The staples are a 1/4" crown X 1" long. Adjust the air pressure for a slightly recessed head.

Shoot the crown across the grain.  Be careful not to blow completely through the 5.5mm ply.  Easy to over shoot.

For Clamping the underlayment with the Titebond you need to evenly apply 175 psi for max strength.  Franklin adhesives is great help.  Phone number on bottles.

If you can not achieve the clamping spec then use the polyurathane.  It is not pressure sensitive however it is only rated at 700 psi strength.  Titebond II and III is rated at 3500 psi.

When clamping layers  together on a jig, use a slightly taller layers on the outside to provide an inside gully to catch the excess adhesive. The tighter the radius the longer the clamping.  Max time 24 hours.

Tightbond standard sets hard with minor setback.  Titebond III has longer open time and has a larger setback.  Adjust jig use accodingly.  Use an Armstrong S-50 notched trowel to spread the Titebond.  Cartridge application with the poly.

I am offering my jig free to any one who wants to come and pick it up.  I am off  I-95 at the PA/DE state line.  I'll also show you how to use it.

These are the shapes you can make:

The Home depot plywood is NOT guaranteed to be void free.  Guaranteed void free undelayment is available through floor covering supply houses.  HD plywood generally speaking, has been a disappointment.