What are the merits of using granite for jointer fences? I can appreciate the fact that the material is stable, beautiful and can be machined to incredible tolerances.
So what? If the fence is set at 90 degrees, and holds that setting, but isn’t perfectly straight along it’s length then the worst that happens when edge jointing is that the board will skew slightly across the blades. If face jointing the purpose of the fence is to trap the board against a reference surface. If the fence isn’t perfectly straight the worst that happens is a slight skewing across the blades during the cut. Are the benefits related to the fact a granite fence won’t twist along its length?
I’m not being a critic here. I can fully understand the merits when used for tablesaws and bandsaws. I’m simply looking for a good explanation of the benefit(s) in a jointer application.
Enquiring minds, etc., etc.
Replies
Ron
Once granite is machined, that's it. It doesn't move. At least not enough to disrupt the woodworking principles of flat and square.
Cast iron, as many Taiwanese manufacturers seem to be finding out, still moves quite a bit. That's why so many folks come on here complaining that their fence is twisted, or their saw top is not fat, etc....
Old American manufacturers of the best woodworking equipment ever built, i.e. Oliver (the old stuff), Northfield (still in business in Minnesota), Tannewitz, etc.... used to set their castings outside and let them set a spell. I was talking to Jeff from Northfield one day regarding my jointer, and he told me that they set their castings outside for 7 to 10 years before final milling. That gives them ample time to season, move, and become ridgid.
Granite doesn't do that. It's been seasoning underground for millions of years.
Jeff
Not necessarily critical when surfacing a face, Ron. But.. twist and cup on cast iron fences can be a major problem when edge jointing for glue-up. Cast iron can warp if stress was picked up in the casting process and even with extreme quality control that can happen.
And to add to that problem.. a jointer fence is usually much thinner than a TS top.. etc. The thinner cast iron is.. the more chance if stress exist that it will rear it's ugly head.
My jointer fence is dead flat.. and it doesn't rust for some reason or other. ha.. ha...
Sarge..
Edited 1/18/2008 11:28 am ET by SARGEgrinder47
Sarge, what kind of mortiser do you have in the background of pic 1? Mike
The "beast" is the last Bridgewood Industrial floor mortiser that Curt Wilke had on hand when he dis-continued the sale of machines. It is the same mortiser you will find on the Grizzly web-site under 4814 with the exception of the Griz is 3 phase.
The Grizzly goes for $2195 and was priced closer to $3000 before a mark down this year. I paid a whopping $800 for it new after I called a friend that owns a custom door shop in the Atlanta metro area and he offered me $1000 sight unseen without knowing it was new.
That was my justification for jumping on it for use and investment. At this point simply..... It isn't for sale as it is very fast, precise and a blue collar work-horse. I just finished 16 mortises on face frames for a chest of drawers and it took under fifteen minutes.
Regards...
Sarge..
Edited 1/20/2008 12:42 pm ET by SARGEgrinder47
Sarge, I was having a great day, until you related this. Now I'm sick, and don't want to live anymore.
I'm just getting into several pieces that will require many mortises, and until my profit justifies a bigger machine, I'm tied into my bench top model. It's ok, but not for the amount I'm hoping to be cutting. The amount of time you're talking about just makes me drool.
Have a great day, even though mine is ruined. (just kidding)
Jerry
I have been droolling over a floor mortiser for years Jerry. My main joint is an M&T which I used to cut by hand. I got a Shop-fox benchie and that speeded matters, but as you know a benchie is limited in capacity. And there are literally handicapped with proper hold-down clamping.
I wanted the Power-matic floor model and could not justify the price either. I watched E-bay and local for two years and could never find a used one. Once someone has a floor model, they won't usually part with it or they want about what they paid for it as the supply for used is low and the demand is high.
I got excited when Curt offered me this for $800. But.. I still had to wrestle in my mind with that's a lot of money to cut square holes in wood. So.. I called a friend in the door business mentioned and after his offer, I jumped on it as I knew I was stealing it at that price. And if worst came to worst I can get my money back and make a profit.
That's all it took to write the check and prepare to wrestle with 650 lbs. on the receiving end. And wrestle we did getting that little puppy on a custom mobile base, which by the way he threw in for free. Some days you just get lucky.. ha.. ha... ha..ha.. ha..
Sarge..
Not that anyone ever does it, but a bowed fence could cause problems when using a jointer to cut a rabbet.
-Steve
Ron,
If the whole equals the sum of the parts, then you have to have some assurance that the rest of the machine is manufactured and assembled to the same level of accuracy.
I would suggest that it is a nice to have, but certainly not critical for most jointing requirements. With many woods, your table saw will put a better edge on the piece if the blade is good. The jointer does its best work getting the first face flat.
We tend to think that the machinery has to be accurate to .00001" but our hand tools are acceptable at the "pretty damn good" level of accuracy.
Don
Edited 1/20/2008 6:15 pm ET by Don01
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