for people who do spring joints at times

[Tom Bussey]

Yes I know spring joints can be put it on a jointer. But why got the extra work. The splits in the boards I am referring to is when tops are glued a crossed the width not length. And I get asked to repair a lot of these splits in the middle of the board, not the glue joint. So we are back to the original question why go to the trouble of doing it it it doesn't add anything to the glue up. The also used to bleed people to get the bad blood out in George Washington's day. How much good that that do him? Check history.

If some is good why won't more be better. and most people tend to overdue ( original question, is there a formula for the gap you make? I did .013 on boards that are a final of 26" long. It might be a bit heavy.) Now we have to have a formula and measure the spring.

So back to another of my questions why do it, if it isn't necessary. And why put stress into the glue up in the first place. Correct me if I am wrong but don't the gaps get put in both faces?

And again did the extra work add any value? And it is a rhetorical question because the answer is no.

[Warren Lake]

I answered your statements, Ive seen non in 40 years in this trade licensed since 84. making up for not owning clamps is kindergarten level stuff. You should call SCM Invincible and Martin up, I think I read both of those machines have a lever to pull so the machine goes into spring joint mode. Important enough that high end manufacturers incorporate it right in the machine.

[Bill Rhodus]

I have the spring joint feature on my jointer. A lever allows the end of the outfeed table, furthest from the head, to sag. I believe a spring joint can be helpful as the ends of the board tend to shrink and swell more than the center.

[Warren Lake]

Bill what type of jointer?

I was just looking at an email from a Toronto dealer and looked at used machinery then saw Martin down the side. Watched a bit and sure enough they do have a handle. Most jointers table goes up and not tilt, says 1.5 so what is that referring to?

spring joint.jpg

[Mel Fulks]

I've never understood how the drop outfeed table of a "pattern makers " jointer could make a hollow joint. I can imagine no way beyond human skill ,and see that as highly unlikely. I worked in
a pattern shop for a couple of years .Old school German guy owned and ran it. He did not have a pattern makers jointer.
Patterns must have have slope to allow easy removal from the sand. I think a side slope AKA "draft" feature is more
likely how the pattern maker jointers were used. Shop had a big ,perhaps 36 " diameter precision disk sander with a
tilting table . That's how we did "draft". Such machines can be found on line ,for sale for use in pattern maker's shops .

[Joe Calhoon]

Warren, my Martin jointer doesn’t have the electronic readout but I think that is referring to depth of cut - 1.5mm. The spring joint is easy on the Martin and is very slight. I used to do spring joint on my SCM JP like you have by dropping in back from the end of the workpiece and pulling out before the cut finished. Then come back and make a full cut.
The old US straight line rips saws could also make a spring joint.
It’s a worthwhile operation that definitely adds value. Won’t show up right away and the customer will never know. Like a lot of stuff we do!

Bill what type of jointer?

I was just looking at an email from a Toronto dealer and looked at used machinery then saw Martin down the side. Watched a bit and sure enough they do have a handle. Most jointers table goes up and not tilt, says 1.5 so what is that referring to?

spring joint.jpg

[Bill Rhodus]

Bill what type of jointer?

I was just looking at an email from a Toronto dealer and looked at used machinery then saw Martin down the side. Watched a bit and sure enough they do have a handle. Most jointers table goes up and not tilt, says 1.5 so what is that referring to?

spring joint.jpg

Sorry to take so long to reply. I have an American 12" jointer. Outfeed wheel does move the table up and down while keeping it on parallel plane with the infeed table. There is however an additional pIr of cams with an attached lever that will allow the discharge end to drop.

[Mel Fulks]

Sorry to take so long to reply. I have an American 12" jointer. Outfeed wheel does move the table up and down while keeping it on parallel plane with the infeed table. There is however an additional pIr of cams with an attached lever that will allow the discharge end to drop.

That is interesting ,and I wondered about that. But decided it could not be that ,since they show wood too narrow to
benefit . Looks to me that Martin method would need some human feed skill. The slightly raised outfeed table method
makes a precise large arc needing only the right height lift ,pre straight-jointed boards. NO skill in guiding is needed to
run the board over the jointer beyond putting down-pressure .

[Warren Lake]

thanks Joe and Mel

Joe what is a MM

Im suprised those old Diehl and Mattison huge tank things I used to see at auctions that looked amazing then sold for 300.00 or some stupid way too low price. Had no idea should have looked at them closer at the controls and studied them a bit. Just want to be aware of stuff and I would have said logically they cant do that so thank you for mentioning that.

Mel you mean those big Old Wadkin sanders. One just sold recently up here and went for a good buck I think 3,500.00 plus buyers premium. What does Draft mean? I know the one where wind blows into your home.

[Mel Fulks]

Warren , Freeman and Kindt-Collins are companies that supply the pattern making trade. The disk sander we had was
made by one of those two. I think Kindt Collins. Don't know if Wadkin made them.
"Draft" is just slope to allow the pattern to be removed from the packed sand.

[Jim Matthews]

I know a few of you here do them any thoughts gap related to length?

Late to the party, but my approach is a little different.

I layup panels about this length.
I do this by hand, using the same plane each time.

It's about 9" long - less than 1/3 the board length.

If I take a shaving from the center, it will eventually "bottom out" and stop cutting.

The difference between the "highest" points at each end and the center is about 0.05 mm or .0019 inch.

Two boards laid up on edge get a gap about the thickness of one sheet of paper.

I leave the outermost boards proud, and plane them to final width after the clamps come off.

****

In practice, I do this to force the error into a repeatable position and assure the outermost edges are reliably tight.

[finlay gray]

0.013 would be hard to do.

[Warren Lake]

after the new knives on 27" I did .003. It clamped very easily and was fine, if anything it was still on the heavy side but if not not much so it lines up close to you .0019. These boards were 7" wide my originals were 2" wide. Final board widths will be 5 1/2" to 6 1/2".

[Rod Sheridan]

after the new knives on 27" I did .003. It clamped very easily and was fine, if anything it was still on the heavy side but if not not much so it lines up close to you .0019. These boards were 7" wide my originals were 2" wide. Final board widths will be 5 1/2" to 6 1/2".

Hi Warren, mine is setup for less, it’s 0:004” in about 40 inches (it’s 0.1mm in one meter)...Regatds, Rod.

[Mel Fulks]

We used a lot of white pine panels. With something that soft you can use more spring. I used as much as 3/32 on boards
About 42 inches long on the Ponderosa and North Eastern white pines. Even with 3 or 4 boards they pulled up and
stayed glued. Sometimes management , especially the roving geniuses clawing their way to fame, will want guys to
bring the material in from the cold and start gluin'. They know they will be in a "better place" when it all falls apart.
Ive seen guys trimming their fresh batch ....all the cut ends falling on the floor.....separated forever from their fellow
board members. Gotta' stop writin'.....eyes are gettin' misty....