I'm new to woodworking, so please bear with my obvious ignornace <grin>. I
recently needed a straight edge to rip stock away from the table saw, I
would also like to use it as a guide for hand router, etc.
So I go to Lowes to buy a Johnson 8ft straight edge for $20. It's two 4 ft
sections that uses a joining plate slipped into the two pieces to make the
8ft length. All I can say is WHAT A PIECE OF GARBAGE. You could never be
sure it was straight because of all the play there was every time you put
the two sections together. I tried using my four foot level to "true" it up,
but that seemed like the blind leading the blind since there was no
guarantee the level was straight all the way its length.
So, my question is where (and how much $$)can one get a reliable straight
edge from 4 to 8ft in length?
All insights appreciated!
If you start with reasonable straight stock this shouldn't take too long
who fully intends to do this, some day
John Doe wrote:
Great article Joe, very insightful (and now I know what "lapping" is). The
problem I see (for me) using this method is that I only have
access/capability of using hardwood for the SEs... I'm sure over time the
wood-made SEs will wear and the edges no longer straight. I would prefer
getting something off the shelf for now to get my work back on schedule. But
great article nonetheless, thanks!
Maybe a piece of square steel tubing. I've seen lenggths in the borgs but
haven't checked them for straightness, but if you try be sure to check a
few against each other, similar to making your own. If three of them match
each other along the length they should be accurate. Untill they get dripped.
That's what I use for my router and circular saw. A 1" piece of square aluminum
tubing bought at a HD like store. I cut a 9' footer in two pieces and attached
the 54 " piece to a piece of 1/4" plywood which was about 12" wide and 48" long
until I ran the saw down one side and the jig saw down the other. Now the edge
the plywood gives me the cut line of the CS on one side and the jig saw on the
other. The other 54" piece serves as a guide for my router. Cheers, JG
Joe Gorman wrote:
will point you to some sources.
But these seem to be gross overkill for most woodworking use. I like
the "sawboard" someone else posted. Seems that it could be made for
the router as well.
Make the obvious change in the return address to reply by email.
I'm a sawboard fan
but I do something different for guiding a router.
This is what I do for cutting 3/4 inch dados, change the 3/4
to whatever size you prefer for a different sized bit.
Cut two pieces of straight 49 inch long stock into guides
(3/4 MDF or whatever floats your boat). The width of one is
from the edge of a my round router base to the far side of
the 3/4 bit. The other is from the edge of the router base
to the near side of the 3/4 bit.
Mark one edge of the dado on the piece of sheet goods to be
dadoed, then use the appropriate near or far side guide to
locate your straight edge and clamp the straight edge in
place. Then run your router along the straight edge to make
your router cut.
You could get by with just a the far side guide most of the
time, but having both gives you more options in how you make
This all depends upon how accurate you need to be. Might I suggest that wood
does not require a really accurate straight edge. If that is so, a straight
piece of bright steel bar may do or a piece of extruded aluminium of an
appropriate section. The larger the section, the more stable the straight
edge. Don't try to fabricate one though. Any welding will distort the beam.
Try a local metal stockist.
You may be able to find a used one. If you can find a company that uses a
calibrated straight edge, they most likely buy a new one every year as it's
cheaper to do that than have the old one retested.
for details of the expensive ones.
Try this one. I have the 50" unit and use it quite a bit.
(Amazon.com product link shortened)
If the wrap gets in your way, go to Amazon.com, then tools and hardware,
then search on Griset.
Bingo Bob, that's about what I had in mind. It's nice to know you can get a
one piece 8-footer for about $99 (as opposed to spending $300 - 500 for a
precision straight edge from Starret, etc).
(Amazon.com product link shortened)
You'll love it, I've had mine for 3+ years, as well as the lighter 36" &
50" models. Before that I used a piece of 1/4"x3" steel flat stock that
I had a machinist true up for me on one edge. I still use it but only as
a straight edge for when I'm scoring long pieces of laminate.
An unkind remark is like a killing frost. No matter how much it warms
up later, the damage remains.
I think you expected the wrong thing from this straight edge. Its designed
to be clamped into place for guiding a router, handheld saw, etc. The idea
is that if you need some fine adjustment, you'll take a straight edge
standard and lay it along the joint of the Johnson guide, then clamp it
down. Using any kind of hand held guide for hand held tools puts you in the
ball park of "good enough" for cutting sheet stock in construction carpentry
or cutting it down to size for later use with more precise tools.
Perhaps what you are looking for would be more along the lines of the guide
described here https://www.popularwoodworking.com/features/fea.asp?id 04
Appreciate the comments Bob, but no, I wasn't expecting too much from the
Johnson guide. My big beef was that it was two pieces in order to rip a 8ft
cut. And if you saw the way the two aluminum pieces butted up end-to-end you
would laugh at how badly they were machined. (I'm slowly learning that
everything at HD and Lowes is good enough for a homeowner that doesn't know
any better.) If I needed to carry around a "straight-edge-standard" just to
"straighten-out" my straight edge every time I needed it, then it kinda
defeats the purpose of having a "straight edge"...lol!
Nope, all I was looking for was a reliable one piece 8 ft straight edge that
would allow one to make smooth cuts with a skil saw or router. But again,
the insights and comments are appreciated, I'm here to learn like everyone
Oh, I know more about the Johnson, than you might realize. I own one. Your
comments made me think about how I have used it in the past and why I think
its a useful guide. The keyword here is "guide". Its shaped just right for
clamping down with small C-clamps and using to provide a guide for your saw
or router. Its stable and smooth and does that job just perfectly. That's
something to consider - smoothely guiding a 2-3 HP handheld saw or router.
You need something that is sturdy and thick enough that you can safely press
the whirling dirvish against it with confidence.
Last year I made some heavy duty shelves for my garage that required routing
a bunch of 3/4" wide slots in a bunch of 2x4's. These slots needed to line
up reasonably well, so I clamped them together in groups of eight with pipe
clamps, clamped down the Johnson straight edge and routed away. It was
Judging by your comments, I assume you did buy one. Its not obvious in
looking at one on the shelf that there are hold down screws to make sure the
two pieces stay together during the job.
When I cut sheet stock, I always measure from the factory straight side of
the plywood or whatever at multiple points and mark it, then lay down the
straight edge along those marks and clamp it down. In fact now that I think
about it, using a "straight edge standard" to line up the Johnson is
something I may have done once - but that is not how I really use it. The
other thing - I use the heck out of 1/2 the Johnson. Would I want a one
piece 8 foot? Yes, but not without having a shorter version to go with it.
You've received all kinds of information in your query. That's what I like
about this conference. It arms you with facts, viewpoints and information
with very little BS so you can make your own decision.
I've got a similar guide, although I don't know the brand name. Even
with the hold down screws, there's some give in the middle when clamped
at both ends.
Since it's often impossible to clamp in the middle, I drilled a small
hole sized for a finishing nail. I don't have to drive the nail in very
far to stabilize the middle, and the resulting hole is next to invisible
for the kinds of projects I'd be using the guide for.
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