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Getting a straight edge without a straight edge?

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Forum topic by Jeppedy posted 08-29-2014 12:01 AM 1630 views 0 times favorited 21 replies Add to Favorites Watch
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Jeppedy

9 posts in 838 days


08-29-2014 12:01 AM

Topic tags/keywords: jig tip tablesaw jointer

Okay, I want to build a router table.
The skins on it are larger than my TS.
so I need to build a panel sled
To build a panel sled, I need a straight board to use as a fence for the sled
To get a straight board, I need to use a jig to ride against my TS fence, clamp the stock to it and rip a straight cut ( poor man’s joiner )
To build the straight cut jig, I need a straight fence to make the cut to give a straight fence…
See where this is going?

How does a new woodworking hobbiest without a jointer get his first “straight enough” fence to continue making and tuning jigs over time until things are all pretty straight?

Buy a fairly straight 2×4 as the panel sled fence?
Buy the 2×4 and rip/sand the face straight is hand smooth?
Use two layers of 3/4” ply, glued, using the face as the fence face?
Tell my wife I need to buy a joiner? :-)

-- Jeff, Newbie from Northwest Indiana


21 replies so far

View ScottKaye's profile

ScottKaye

471 posts in 1416 days


#1 posted 08-29-2014 12:13 AM

A sheet of MDF is pretty darn straight on its edges

-- "Nothing happens until you build it"

View sawdustjunkie's profile

sawdustjunkie

343 posts in 1180 days


#2 posted 08-29-2014 12:15 AM

Are you talking about cutting a straight edge on plywood?

-- Steve: Franklin, WI

View Loren's profile

Loren

8302 posts in 3111 days


#3 posted 08-29-2014 12:33 AM

Got a 24” or larger bubble level? Those are
straight generally.

Lacking a jointer and planer is a limitation for
more precise woodworking unless you are willing
to acquire and learn to use hand planes, with
which flat and straight boards can be made.

View TheFridge's profile

TheFridge

5765 posts in 949 days


#4 posted 08-29-2014 12:38 AM

See if a cabinet shop with a jointer can do it for you.

-- Shooting down the walls of heartache. Bang bang. I am. The warrior.

View sawdustjunkie's profile

sawdustjunkie

343 posts in 1180 days


#5 posted 08-29-2014 12:38 AM

You can edge joint with a router table! I have had great results with that method.
I have a planer, but not a jointer. I can get a good smooth edge on the router table with stock up to about 1.5 inches. That is 6/4 wood.

-- Steve: Franklin, WI

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TheFridge

5765 posts in 949 days


#6 posted 08-29-2014 12:44 AM

He could… If he wasn’t trying to build one :)

-- Shooting down the walls of heartache. Bang bang. I am. The warrior.

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sawdustjunkie

343 posts in 1180 days


#7 posted 08-29-2014 12:48 AM

OOPS!!! Forgot about that part.

-- Steve: Franklin, WI

View Grumpymike's profile

Grumpymike

1917 posts in 1778 days


#8 posted 08-29-2014 01:26 AM

“There is a hole in the bucket dear lizah” .....

make your piece to slide (kind of tightly) in the miter slot, screw your plywood, MDF or other base to it and run it through the blade … You now have one straight edge … Use a framing square to mark and align the fence, you now have a 90 degree straight edge. ... Oh look! it looks like a sled, or as the say in Boston a table saw boat.

By skins, I assume that you are referring to the case carcass; rip your pieces from the 4×8 with a circular saw a bit over sized then true them up on the table saw … much easier to handle.

Now, if you still want to joint a fence, place your 2×4 against the right side of the blade, move the fence over till it just kisses the stock, remove the stock and reset the fence 1/32 closer to the blade and run it through, now flip the stock over so that the just milled side is against the fence and take another 32nd off that face.
Let the stock sit over night and see if it is still straight the next day. (Kiln dried wood will sometimes “case harden” and warp or twist after you remove that hard skin on the wood)

I hope this helps and that I didn’t misread your question.

-- Grumpy old guy, and lookin' good Doin' it. ... Surprise Az.

View Sarit's profile

Sarit

514 posts in 2603 days


#9 posted 08-29-2014 01:26 AM

Buy a straight edge clamp and you can make as many straight edges as you want.

Bora 50-in straight edge clamp $40

For crosscut sled fences, I used plywood as the material since its less likely to warp w/ changes in humidity and lighter and stronger than MDF.

If you got $$$ then invest in a track saw system.

View timbertailor's profile

timbertailor

1592 posts in 887 days


#10 posted 08-29-2014 02:31 AM

This is a good, cost effective solution for getting a straight\reference edge on the table saw. I use it more for tapered legs and such but it does come in handly.

-- Brad, Texas, https://www.youtube.com/user/tonkatoytruck/feed

View Jeppedy's profile

Jeppedy

9 posts in 838 days


#11 posted 08-29-2014 02:43 AM

Thanks all! What I think I’m hearing you say is I could generally just trust an MDF (and maybe plywood) stock edge. Also sounds like people are generally comfortable with a reasonably straight 2×4.

Thanks for all the suggestions!! I’ve got to get me one of those straight edge Bora guides!

-- Jeff, Newbie from Northwest Indiana

View firefighterontheside's profile

firefighterontheside

13470 posts in 1320 days


#12 posted 08-29-2014 02:45 AM

It’s hard to find a straight 2×4 that is straighter than the edge of a sheet of MDF.

-- Bill M. "People change, walnut doesn't" by Gene.

View skatefriday's profile

skatefriday

380 posts in 946 days


#13 posted 08-29-2014 02:54 AM

” table saw boat.” bahahaha. I like that.

And yeah, OP, I think you are asking the question that a ton of
new woodworkers have had but don’t ask.

You watch the Wood Whisper’s video on building table saw sled/boat
and he takes a nice piece of 8/4 scrap hardwood and runs it through
his jointer. Well I had neither 8/4 scrap, nor a jointer. So I laminated
two pieces of 3/4” plywood together. It was kind of straight but not
really. So I did it again and this time put an L shaped backer on it. Better,
but not perfect.

I’ve heard that a scrap of corian will work very well and am currently
on the hunt for one of those.

But yeah, I love the tutorials that say, “To get a straight reference edge
take this other straight reference edge and do … “

Really? And the chicken magically appeared at my doorstep.

View MT_Stringer's profile

MT_Stringer

2853 posts in 2694 days


#14 posted 08-29-2014 03:20 AM

This works for me.
http://lumberjocks.com/projects/103276

-- Handcrafted by Mike Henderson - Channelview, Texas

View HorizontalMike's profile

HorizontalMike

7146 posts in 2377 days


#15 posted 08-29-2014 10:51 AM



...make your piece to slide (kind of tightly) in the miter slot, screw your plywood, MDF or other base to it and run it through the blade … You now have one straight edge … Use a framing square to mark and align the fence, you now have a 90 degree straight edge. ... Oh look! it looks like a sled, or as the say in Boston a table saw boat.

By skins, I assume that you are referring to the case carcass; rip your pieces from the 4×8 with a circular saw a bit over sized then true them up on the table saw … much easier to handle.

Now, if you still want to joint a fence, place your 2×4 against the right side of the blade, move the fence over till it just kisses the stock, remove the stock and reset the fence 1/32 closer to the blade and run it through, now flip the stock over so that the just milled side is against the fence and take another 32nd off that face.
Let the stock sit over night and see if it is still straight the next day. (Kiln dried wood will sometimes “case harden” and warp or twist after you remove that hard skin on the wood)
Grumpymike

Grumpy has it sewed up here.

The only thing I might change, is the notion of using a 2×4 mostly because it is soft wood. Your boat/sled will be much better with a hardwood fence. Buy TWO 1×6 pieces of hardwood from the big box store (think oak or at least poplar). Glue them together in order to double their thickness. Run the glued piece thru the TS rotate it and run it thru again. Now you have the makings of a nice hardwood fence that will keep that plywood base/floor straight over time.

Hardwood lasts. My sled is +3yr and counting. Still straight as an arrow.
http://lumberjocks.com/projects/57667

-- HorizontalMike -- "Woodpeckers understand..."

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