I’m novice woodworker and have begun projects with larger tabletops that require me to glue boards together to achieve the necessary table width. For my first project I ripped boards and glued them together but had a real hard time keeping my cuts lined up. I’ll explain.
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If I rip a board in half and then try to but them together on the rip I get a bowed effect where the ends (front and back) match nicely but the middle 2/3 has a substantial gap. Making it impossible to use as a tabletop.
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I’ve begun to ignore the setting on my table saw that tells me if I’m 90 degrees. The positive stops may need tinkering with since I’ve moved this saw across the country and back again. (Don’t ask). Instead I use my square to line it up. Maybe my crooked eyes are playing tricks but it sure looks true to 90 degrees.
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This may be all for not since my account (wife) has pre-approved the purchase of a jointer. But I would still like to figure this out. Is it how I might be pushing the wood through the saw? Is it my fence? It’s a decent enough contractors’ grade saw. Could it be the blade. I’m using a Feud ripping blade.
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Anyway I’m at a loss. Any help wood (no pun intended) be greatly appreciated.
Replies
Very often, ripping a board, especially in half, will cause the boards to bow or warp. The wider board was cut from the log and dried as a single piece. When you rip it, it releases tension and changes the integrity of the wider piece. That's not to say your ripping technique is perfect, but even if it is, you can still have pieces that will move through no fault of your own. I always use a square for setting up the saw blade. It is important that your saw is tuned properly. Table saws and jointers go together. Whether you joint by hand or power, you need nice straight edges on the saw if you expect any real accuracy, it adds safety, too.
Beat it to fit / Paint it to match
Cicco,
I've been chasing that same issue for over a year now and, as Hammer said, boards move after cutting. However, I did find that my fense 'face' was not perfectly flat, that is, there may be a bit of a bow in the face. I pulled fense flush with the miter slot and checked...and shimed. Also, I put a straight edge between the stock and fense and that improved the cut. To get the seams perfect, I clamp the boards together and take a few passes with the #7...usually you can't see where the boards were joined when done.
I had a good look at my fence. I put my long square on it and found that it too had a slight inward bow in the middle. I even had a 3/4 inch strip of maple plywood attached to it.
Thanks for the advice. I'll try to shim it. May be time for a decent after market fence.
Edited 3/15/2006 9:40 pm ET by Cicco
What kind of table saw do you have? If you're using a Craftsman with a stock fence, you're fighting a losing battle. Craftsman saws (and most other "homeowner" brands) are capable of decent cuts but need some serious tuning up to get there. You also need a good blade - and a good fence is absolutely essential.
You will also improve your saw's performance if you use machined pulleys and a link belt instead of a V-belt. Also, make sure that your motor and arbor pulleys are aligned correctly. You'll be amazed at how much vibration is eliminated with these "tweaks".
Finally, do you have an outfeed table? Ideally, you should only be pushing the board thru the cut without worrying about "steering" it - or trying to support it.
Its an IMC (??) I bought in the buy and sell. Its a contrctors grade 1.5 horse, belt driven...
Can you explain what you mean by an outfeed table.
I've never heard of an IMC brand, but - if it's a second hand contractors saw - it probably needs some tuning up before you're going to get any decent cuts on it.
Here's a picture of my saw & outfeed table setup - and the table is even pretty clean for a change - lol. I use the table for a work bench as well as an outfeed table so it's sometimes a hassle having to clean it off for long rips.
You can also get some roller stands to support long workpieces. They work pretty well as long as you're careful to keep the rollers aligned right. If they aren't perpendicular to the blade & fence, they want to "steer" your workpiece
Here's the web site where the saw was orginally purchased.
http://www.protoolcity.com/imc_table_saws.htm
Outfeed table. Now I see. I'll give it a try. I'll have to ask Santa for a new fence. It took me months to convince my accountant (aka wifey) that I need a jointer. One step at time seems to work best in securing the pre apporved purchase of large ticket items.
I like your idea over the roller system. More bench space can never be a bad thing.
That actually looks like a pretty good saw. I guess it is a Canadian brand. If you have the fence that is pictured, it looks like a Beis clone, that is a good thing. I am now thinking you should spend the time to dial in the saw, align the blade to the miter slot, set the bevel stops and square up the fence parallel to the blade. This all sounds easy but expect to spend half a day to get it right. If the fence is more 1/32" bowed and it is the same as in the picture you should be able to order a new fence for $60 or so bucks. Of course it could be bawed as well. If your fence is not the one pictured then it may not be worth messing with.
Mike
Looks a lot like a Jet saw. Does Jet sell under another name in Canada?
Whatever it is, it looks better than I was expecting. Most of the used saws I see have definitely been USED!!! - lol
If you haven't spent the joiner money yet, put it into a good tuneup and fence for the saw. Joiners are nice, but a good saw is indespensible.
I was thinking Jet as well.
Maybe Jet translates into IMT in Canadia.
Heh heh.
i've read many informative responses to your table saw dilema. maybe i can add to your confusion by giving another opinion.
the wood you select should be dry enough for furniture use. i'm also one who still beleives that narrow pieces glued up for a large piece will remain flat and with less internal stress. how it looks will depend on how you arrange your pieces.
not even knowing the length of stock you're ripping, i wouldn't be too concerned if the entire edge on adjoining pieces fail to touch all the way down. this is because a properly adjusted jointer with CORRECT use will remove any imperfections and make the edge straight.
but if you're still worried about the ripping then follow the advise already given. be sure the blade is parallel with the fence. check to see the fence remains locked at BOTH ends as you rip. proper ripping technique is essential for an accurate cut. keep in mind you'll never get a finished edge from the ripping operation.
hope i've helped some. good luck!
Edited 3/23/2006 1:17 pm ET by samuel
I had a question - it is my understanding that rip blades - being thinner - can warp if the feed rate is too fast or the material really dense. Also, I never heard of edge jointing after a rip cut if the joints are to be exposed like on a tabletop where perfection is demanded. I think a jointer (either powered or hand plane) would be an essential step in creating a tabletop from more than one board - am I wrong?
I have run into similar problems where even after running the boards through the jointer they do not line up perectly and it is due to the limitations of the jointer process and poor technique on my part. I look forward to further comments as I thought after buying a jointer to make my table top construction would go well and it hasn't yet - I was told to buy wood putty to fill in the cracks but I rather work on perfecting technique and results than covering up poor results.
Can the original poster post a pics of the boards as they look with the imperfect joint? maybe that would help in figuring out a solution. -Tom
Rip blades aren't always thinner.
Some rip blades are called "glue line rip" blades, as an assertion by the maker that the resulting cut is good enough to glue without jointing.
There are a couple ways you can joint "wrong."
One is, you haven't got the edge to be a section of a plane. If this is the case, when you put two such boards in position to be glued, either the ends won't be together, or the middle will not meet. In this case, this means you need to improve your jointing technique, get a larger jointer (a jointer can't effectively perfect a piece of stock more than about twice the length of the jointer), or adjust the height of your outfeed table.
The other way to get it wrong is if your fence isn't at exactly 90° to the table. If you just can't get it adjusted right, you can still make a gluable pair of boards by changing how you edge-joint one of the boards. If, for example, you pressed the show side of board A against the fence when jointing the A-B edge of board A, then press the underside of board B when jointing the A-B edge of board B. Then if you're off by a degree or two, the two boards' inaccuracies will match each other exactly, and you'll get a fine gluing surface. As others will point out, it's better to get the fence exactly correct, but if you can't...
Hope this helps at least a little. You're definitely going the right direction, wanting to get your stock straight and square.My goal is for my work to outlast me. Expect my joinery to get simpler as time goes by.
Re: your first comment, you're thinking of "thin kerf" rip blades, which are marketed to improve ripping performance of "underpowered" table saws (e.g., 1.5HP contractor saws). New design and engineering seems to have made them more reliable than when the were first introduced.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
From what i understood there are rip blades and there are thin cut rip blades. i use a thin cut because it takes less pressure to feed the stock thru.
Maybe i misunderstood your initial problem. i thought you were ripping stock into narrow pieces then regluing them (edge to edge) to make a large tabletop. if thats incorrect then i'm sorry. if that is correct then i ALWAYS joint edges for gluing, especially a tabletop but maybe not a workbench.
A ripped edge should be a straight edge but, at least for me, is not good enough for gluing up a tabletop. Thats my opinion.
I know i'm not the smartest person when it comes to knowing everything about woodworking, but i did teach H.S. shop for 27 years and you learn to do quite a few machine operations.
I think it comes down to this, you can lose many imperfections on an edge, made by a table saw, with a jointer. This is where time and technique are critical. you need to practice and practice correctly.
You still haven't mentioned how long your boards were. And by the way what's the table length on your jointer?
If there are gaps in the joints, they aren't going to last long. A good joint will have no gaps and if it does, they shouldn't be noticeable. Sure, you can fill it with glue, but the glue won't take finish or look good. Rather than use a band-aid, I would work on the jointing technique, whether it's powered or by hand. If the two pieces being joined have a tiny gap in the center but that gap goes away with clamping pressure, it's usually called a spring joint and will work fine. The glue joint should be stronger than the wood itself and if the joint is tested, the wood should fail rather than the jointAs far as a blade warping, excess heat can and will damage a blade. If you ever warp one and you get the wood through, leave the saw running and it will usually flatten out. Turning the saw off pretty much guarantees a potato chip (stand back- it's not the most pleasant thing to watch or be near). A blade that was overheated but remains flat can be re-tensioned by a knowledgeable shop. Thin kerf blades are for reducing cutting resistance on lower powered saws, as far as I have always heard. If the saw has enough power to get through most woods, I would use a full kerf blade.
"I cut this piece four times and it's still too short."
What is a #7?
It's the one between 6 and 8.
And in hand tool world it refers to a #7 Stanley jointer plane, for those that can't handle a #8!
I'm outa here.
Most likely the #7 they are referring to is a Stanley #7 plane
Several points. First, I don't understand why you are ripping boards in order to glue up wider tops. Its a myth that you using narrow boards will reduce warping. The narrow boards often create esthetic problems, and also increase the work needed to join the boards.
There is a simple way to determine if your blade is set at 90° relative to the top. Take a flat board, with a constant thickness, and crosscut it at 90°. Then lay the boards on the tablesaw top and flip one of them over. If the two cut edges don't touch at both top and bottom the blade is not set square. If you keep track of how the boards were cut you can determine how to adjust the blade.
Ripping a board won't automatically create a straight edge, since if the edge running against the rip fence is bowed, the resulting rip cut will be curved also. You can tack a straight edge onto the board to be trued up and run that straight edge against the fence. Then with one edge trued up, you can run that against the rip fence to make the second edge straight.
Straightening edges is so much easier with a jointer. You can achieve the same thing with hand planes, but there is a bit more learning that must be done.
You mention that you do not have a jointer yet. Hence, I assume that your boards have not been face jointed or edge jointed prior to ripping,which is the proper milling sequence. What is likely happening is that the edge that runs against the fence is not straight, and that ripping merely produces a second edge parallel to that first edge. You need a properly jointed edge to start with.
Just my 2 cents worth...
Best regards.
Guy
Cicco,
A gap in the middle 2/3 is ideal for joining a table top as long as the gap is small enough that it can still be closed with clamps. This clamping situation keeps the board ends under pressure and prevents glue failure later in the joint's life. This technique is practicall universal to Eastern and Western butt joints.
Cicco:
A little advise from an "old timer": Before you buy any more tools, tune-up your table saw, and if you do not have one, install a good after market fence.
Any tool that is not adjusted properly is dangerous, especially a table saw. Many articles are available on how to do it, and in which sequence.
You should then be able to rip boards accurately, and fine tune the joint with a hand plane. Be patient!
Until you get to more advanced work, a jointer could wait.
HL
A board that has an inconsistent moisture content ie. one that is dryer or wetter inside such as a board that had a high moisture content and was brought into a dry atmosphere (a heated workshop in winter) can bow when ripped.
Ain't that a fact? - lol I was once ripping some common pine and it was bowing pretty much as it came off the saw, but I was able to deal with it. One piece started bowing and suddenly exploded (literally!!). I had ripped about 3' and it split the rest of the way (about 3'-4') all by itself. Scared the bejesus out of this child! - lol
You have recieved a lot of good advice. Unfortunately it is hard to get good results without a jointer. However I suspect you saw is suspect. Heh heh. I am not famuliar with IMC, that is not a good sign. There are really only a few decient contractors saws out there. A good fence will set you back at least $250. If you start looking you can likely find a used saw that has a better fence and trunnion system for $300 to $400.
Mike
I agree with those who say to really give your saw a good tune-up. When you're done and you rip your test board, pay careful attention to technique. I'm still working on being "perfect every time" when I feed a board for ripping. It's possible to get realllllly unusual shapes if your technique is off, LOL! OK, that's an exaggeration, but seriously, technique will make a difference. If at all possible, use a featherboard just in front (user side) of the blade to hold the stock against the fence.
Doesn't seem like the blade would do that. I use a Freud rip also, they're good blades.
"I’ve begun to ignore the setting on my table saw that tells me if I’m 90 degrees." Not a bad idea. The stop of contractor's saws doesn't seem to be all that reliable.
forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
Edited 3/20/2006 12:06 pm by forestgirl
A feather board is on the wish list. I've read my manual (again). I'll give trying to tune it up a go. I'm sure its got some to do with my technique. I need to set up an outfeed table. I think it'll help cause I'm always worried about were the piece is going once it passes the blade.
"...cause I'm always worried about were the piece is going once it passes the blade." Good thing to worry about, but it interferes with other thought processes -- not good.
If you're not set on a particular type of featherboard, you might want to look at the Grip Tite Magnetic FB. It's great for ripping, easy to set and move. Here's their web site:
http://www.grip-tite.com/
I have three of them, and use them for more than just a featherboard.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
It's easier to make a featherboard than it is to get in the car and go buy one, as long as you have a bit of scrap and a clamp to attach it to your fence / TS top. Less than ten minutes to make your first one, future ones will go faster.
EDIT: Not disputing the utility or convenience of commercial devices, just saying you don't need to wait for disposable $$ to get the safety benefit.
My goal is for my work to outlast me. Expect my joinery to get simpler as time goes by.
Edited 3/21/2006 2:19 am by John_D
Why is a feather board on a "wish list"? If you need one and have wood scraps, make one. You'll need a flat head screw, a piece of wood to cut the slots that make the feather board, a piece of wood (preferably something hard with grain like maple) that fits and binds into the miter slot, a knob and a couple of washers. If you need a visual, go to a woodworking store and look at one. Rather than put the hold down on it (which I have yet to find useful), I would make another feather board that attaches to the saw fence. When I made mine, I used a jig saw and the cuts aren't perfectly straight but it stays in the slot better than the one I bought, which wants to move no matter how tight I crank the knob. That one has a piece of aluminum in the slot and I think the expansion slot in it needs to be longer so it will flex more.
"I cut this piece four times and it's still too short."
My feather boards are even simpler. One piece of wood, long enough to clamp to the edge of my saw.My goal is for my work to outlast me. Expect my joinery to get simpler as time goes by.
That works, too. I prefer to have the clamping point closer to the blade, but either way is better than no feather board.
"I cut this piece four times and it's still too short."
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