Sofa-bed continued:
After having assembled/disassembled the sofa-bed several times I felt that the 19/32 plywood the End Pieces were made of wasn't sturdy enough.
I looked at 23/32 thick plywood at Lowe's but decided to double up the 19/32 plywood instead. One reason was that a 4' x 8' sheet of the 23/32 plywood was just too heavy for me to comfortably carry around.
Working with plywood sheets means I'll be using my circular saw instead of the table saw. It's too unwieldy to try and maneuver a full sized plywood sheet on the small table saw I own.
When using the circular saw I usually draw a line then follow it using the guide on the front of the saw.
The problem with a circular saw is that when I'm done the cut is never dead straight. No matter how careful I cut there are always minor variations. Then if I measure the next cut off this edge the error is just compounded. Before I started I wanted to see if I could come up with a better method.
This is what I came up with. It does take extra time setting it up but I think the results are worth it.
When I was at Lowe's buying metal stock for the sofa-bed I bought this.
It's an aluminum bar that's 1" wide by a 1/4" thick and 4' long. I ended up not using it in the build but I found it really handy for use with the circular saw. It's fairly rigid but not very heavy.
First figure out where you want to make your cut.
Next measure the distance from the outside edge of the circular saw blade to the edge of the saw's base plate.
On my saw it's 1-9/16". Of course this might be different for other brands of saws.
Now's where it gets interesting. You want to set the aluminum bar so it will act as a straight edge for the saw. But you have to plan the cut so the short side of the saw's base plate is in contact with aluminum bar. This means that on some cuts you have to figure in the width of the saw blade. In my case that's a difference of 1/16". So sometimes the bar is offset 1-9/16" and other times it 1-5/8".
Hopefully this will make it clearer:
After you have figured out the bar offset, stop and do it again. It's easy to make a mistake at this step. After you've done that twice go ahead and measure then clamp the aluminum bar into position.
Using the circular saw with the aluminum bar as a guide is so much easier than having to concentrate on trying to following a line. It's more of a hassle to set up but after I made that first cut I could kick myself for not having come up with this before. You can just breeze through a 4' long cut. When you set the clamps don't let the ends overhang the edge of the bar so that they would interfere with the saw base plate.
Woodworking tip. A garbage can can double as a saw horse. The hand saw is to help clean up the plywood which can splinter at the end of a cut.
Pretty soon that 4' x 8' sheet of plywood has gotten a lot smaller. Make the final cuts for the new end pieces.
Here is the new Left End Piece with the original.
Clamp the two pieces together. Before I removed the hardware from the original piece I marked their position so I'd know which holes to duplicate in the new plywood and which to ignore. Drill those holes now.
Remove the clamps and squeeze wood glue all over one of the Left End Pieces.
Use a brush to spread it around.
Clamp the two Left End Pieces together. Put bolts through the common holes and with nuts and washer screw together.
I let it set for a day before removing all the clamps and hardware. Then I did all the same steps again for the two pieces that will make up the Right End.
continued -