LumberJocks

Edge jointing on table saw questions

  • Advertise with us

« back to Woodworking Skill Share forum

Forum topic by nickbatz posted 08-02-2018 07:53 PM 1848 views 1 time favorited 46 replies Add to Favorites Watch
View nickbatz's profile

nickbatz

238 posts in 497 days


08-02-2018 07:53 PM

Topic tags/keywords: joining

Edge jointing novice here with some questions, please.

1. Re: Izzy Swan’s video, is there any reason not to make individual “bar clamps” out of 2×4 lengths with a fixed block at one end and a block + a wedge at the other?

Izzy uses a plywood sheet to make a “clamping board,” but I’m cheap. :)

https://www.youtube.com/watch?v=ot6jE9PTWV0

2. Why do the edges of, say, a 2×6 dimensional board you buy at Home Depot need a jointing jig rather than using the table saw fence? Are the edges really not parallel?

I’m going to trim off the rounded edges anyway, so I guess I could just look for myself…

TIA


46 replies so far

View Richard's profile

Richard

11274 posts in 3449 days


#1 posted 08-02-2018 08:13 PM

“I’m going to trim off the rounded edges anyway, so I guess I could just look for myself…”

That’s a good idea.

-- Richard (Ontario, CANADA)

View nickbatz's profile

nickbatz

238 posts in 497 days


#2 posted 08-02-2018 10:31 PM

I just experimented on two old 2×8 boards using the fence, first one side then the other, and yeah, there’s a tiny bit of daylight in the middle.

What I don’t know is whether the boards being warped has anything to do with it, i.e. whether a jig will make a huge difference?

View nickbatz's profile

nickbatz

238 posts in 497 days


#3 posted 08-03-2018 01:55 AM

(I mean I cut one side against the fence, then turned the board over and cut the other side.)

Next question: there’s just enough daylight in the middle of the joint to push a piece of paper through. Will a jig using toggle clamps get rid of that?

Or can you just use a belt sander to even out the edges where there a little higher?

View TheFridge's profile

TheFridge

10858 posts in 1902 days


#4 posted 08-03-2018 02:04 AM

Running it against the fence isn’t jointing unless it’s a small enough piece to register fully against the fence the whole way. Now I’d trust a piece of ply registered against the fence with the board to be jointed clamped to it but it’s the exact same principle of what you’re trying to avoid.

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

View nickbatz's profile

nickbatz

238 posts in 497 days


#5 posted 08-03-2018 02:12 AM

Okay, thanks TheFridge… but I don’t quite follow what you mean by the principle I’m trying to avoid.

Also, I don’t get why a small piece or a piece of ply will stick to the fence better than a 1-1/2” thick piece of Douglass fir. Do you just mean that the small piece has less room to screw up and the ply has a factory edge?

I mean, I definitely believe you that it will work! It’s just that I like to understand what I’m trying to do before going off blindly.

These are going to be a little over 30” long, and it’s going to be a round base for a 3” thick 5’ round solid maple tabletop, so it has to be as solid as a Fiat.

View TheFridge's profile

TheFridge

10858 posts in 1902 days


#6 posted 08-03-2018 02:48 AM

The ply has a factory edge that is considered to be pretty straight and dimensionally stable. I’d use a piece almost as long as the stock to be jointed.

I wouldn’t trust a 2×4 or 2×6 to be straight, right off the rack. It (may or may not) need to be surfaced and left to dry til it’s moisture content equalized and then jointed and planed at least s3s.

It’ll still never be as stable as ply.

Not a small piece of ply but a small enough workpiece to register almost full against the fence, before and after the cut.

Think of it this way. If the work piece is 8’ and curved and you register it against the fence you’ll still end up with a curved board. Now it’s the same width all the way down the board. But still curved.

You can make a frame or sled from 2×4s like what I think you’re getting. Find the straightest you can and check it with a 4’ rule or level. You can get it close. It may warp as it dries. It may not. But, I’d still trust ply a whole lot more than wet construction lumber.

Edit: a thicker sled will limit you. If you have an 1-1/2” tall sled trying to straight edge 1-1/2 tall lumber on top of it and your saw only cuts 2-7/8” then you’ll be buying a piece of ply to get more capacity.

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

View clin's profile

clin

1039 posts in 1413 days


#7 posted 08-03-2018 03:28 AM

I’ll second what Fridge has said and restate it in my words if it helps. If the entire piece of your wood touches the fence before and after the cut, you will get a straight edge. This happens because even a curved board (crooked) will touch the fence in the same place on the wood throughout the cut. So it will run straight and not try to curve around the ends of the fence.

I joint on my table saw. I typically do it by using an edge clamp. An edge clamp is sort of like a straight edge that can clamp across something. These are more commonly used on sheet goods (plywood etc) to provide a straight edge to run a circular saw against. By using this, I’m clamping on to my wood to give it a temporary straight edge. This clamp of course must extend past the edge of the board on one side. It’s the edge clamp that rides against the fence.

Because the edge clamp is straight, the resulting cut will be parallel to the edge clamp and therefore straight. I would then remove the clamp, flip the board and can then run this now straight (jointed) edge against the fence to straighten the other side.

Not all edge clamps will work. Most have their clamping handle swing down, and these will hit the table saw top.

Another approach is to get a known straight piece of plywood or other board to act as the temporary edge and then clamp or screw the wood to this.

I don’t think ANY board, and certainly not construction lumber, should be considered straight. However, I would consider using a laminated shelf board. These tend to be very stable, and straight. You can always check with a straight edge.

-- Clin

View Rayne's profile

Rayne

1209 posts in 1956 days


#8 posted 08-03-2018 04:09 AM

you don’t want to put warped lumber on a table saw fence as it could potentially pinch and cause a nasty kickback. If you look over several dimensional lumber, you’ll see just how varied they are. That’s why you’ll see some people (outside of home construction / framing) sit there sifting through each piece trying to find the straightest ones to work with, which will give you the most lumber for your money when you trim off the rounded edges.

View Aj2's profile

Aj2

2321 posts in 2214 days


#9 posted 08-03-2018 04:29 AM

Don’t you guys think it’s a bit of a stretch calling a sawn edge jointed. I understand how straight your table saw or my can edge a board,
But a jointed edge to me is a flat face square to a straight jointed edge.
A table saw can only produce half of this

The You tube teachers must be running out of stuff to parrot so now they are making up garbage just to get views.
Buy clamps for heavens sake

-- Aj

View nickbatz's profile

nickbatz

238 posts in 497 days


#10 posted 08-03-2018 05:31 AM

Thanks for the replies.

Working inside out:

Aj! Izzy Swan is freaking brilliant! I love his videos, and I’ve learned all kinds of things from them.

Ya-uh, the clamping board works! See for yourself. I don’t need no stinkin’ clamps!

:)

*
TheFridge, you answered my question at the beginning of the first reply after mine above. Thanks.

As to the rest… man, it sounds like you’re way, way into areas of woodworking I totally respect but lack the inclination to deal with! When you walk into Home Depot and buy a Douglas fir plank, you don’t need an oven. They have piles of boards to sort through and choose from.

Or if you want to spend more for cleaner DF – which is a different look rather than categorically better – there’s a place called Anawalt Hardware 20 minutes from me in North Hollywood, CA that stocks the kind of wood you’d use for a solid-core door. I used that wood as part of every one of the projects I’ve posted, and it’s just gorgeous. A 1×6 of that stuff might run $15 – that kind of price range, vs. maybe half that at Home Depot. (No idea how much a 2×6 is.)

Oh – I just read Rayne’s post. Yeah, I get why I and other people would sort through lumber at the yard. :) What I wasn’t sure about is how straight dimensional lumber is, and now I do.

And no way, the pieces of wood I cut on the table saw aren’t warped, or if they are it’s not a visible wave or anything. As I posted, I ended up with a test seam that’s perfect in some places but there’s just enough daylight to run a piece of paper through a couple of other areas.

So I need to make the jig, as TheFridge says.

clin, yeah, it’s pretty clear that the cut is going to mirror any bowing on the other side of the wood. What I didn’t know is whether dimensional lumber’s sides can be trusted to be perfectly straight like the factory edge of plywood is.

Okay, thanks again everyone.

If anyone understands what I’m saying about the “bar” clamps, please let me know what you think. And if anyone knows whether it’s worth trying to use a belt sander to mate the pieces that are at most a paper’s thickness off, that question also remains.

View Woodknack's profile

Woodknack

12842 posts in 2797 days


#11 posted 08-03-2018 05:38 AM

I’ve used clamping jigs with wedges for short mitered boxes. They’re nice because it forces the box square and keeps the miters closed. If I were gluing a lot of panels, I would consider a jig like in Izzy’s video. They make commercial clamping jigs that use screws or pneumatics instead of wedges. If you build a jig, just make sure to cover any surface that contacts glue with packing tape or you’ll have a panel stuck to your jig.

-- Rick M, http://thewoodknack.blogspot.com/

View Woodknack's profile

Woodknack

12842 posts in 2797 days


#12 posted 08-03-2018 05:42 AM



If anyone understands what I m saying about the “bar” clamps, please let me know what you think. And if anyone knows whether it s worth trying to use a belt sander to mate the pieces that are at most a paper s thickness off, that question also remains.

- nickbatz


No to the belt sander. You’ll never get the edge good enough for glue up. Look at straight edge jigs for the tablesaw, or buy a jointing plane and get good with it.
Bar clamps are nice. For years I used pipe clamps and they do the job but I bit the bullet and bought parallel clamps and they are the bomb diggity. And as mentioned above, I’ve also used clamping jigs.

-- Rick M, http://thewoodknack.blogspot.com/

View nickbatz's profile

nickbatz

238 posts in 497 days


#13 posted 08-03-2018 05:43 AM

Okay, thanks Rick. I was planning on using finishing wax to stop it from sticking, but packing tape sounds like a better idea.

View nickbatz's profile

nickbatz

238 posts in 497 days


#14 posted 08-03-2018 05:46 AM

By the way, I made a set of Izzy’s corner clamps, and they work really well.

Whether I’ll joint lots of panels is questionable. I have to this time, but it’s my first.

So I’m not going to put any professional flourishes on the jig, I’ll just screw/glue some boards to plywood.

View Woodknack's profile

Woodknack

12842 posts in 2797 days


#15 posted 08-03-2018 05:48 AM

Wax works too, or packing tape, whatever you have that works. That clamping jig probably costs the same as one parallel clamp so it’s economical.

-- Rick M, http://thewoodknack.blogspot.com/

showing 1 through 15 of 46 replies

Have your say...

You must be signed in to reply.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics

HomeRefurbers.com