I am preparing to glue up the top for a coffee table I’m building. After using the table saw to square up the pieces prior to glueing, I am taking a piece of sandpaper to clean up chatter and knock down any high edges.
My question is,
Should I be able to see the seam of the two pieces after glue up?
If yes, how much seam is to much?
Won’t the sandpaper put the wood out of square?
How do I sand evenly across the surface of the joint?
How much chatter is to much and will make a joint beyond fixing?
Thanks in advance,
Charles
Replies
Charles,
Your terminology is a little confusing, but I will try to answer your questions.
If your joints fit properly, you should not be able to see any gap between the two pieces of wood.
Sandpaper, if not backed up by the platen of a belt sander or sanding block, will probably round over the edges which is not what you want.
Are you gluing your boards edge to edge to make a wider board for the top, or end to edge to make a frame for the top? If you have much levelling to do, I would start across the grain until the joint is level, then go with the grain.
Chatter occurs with hand planes, not with a saw. I think you are talking about saw marks - arc-shaped marks on the sawn edge of the board. The amount you get will depend on the quality and sharpness of the blade, as well as how well your saw performs and to a degree, your technique. It is not uncommon for me to get some saw marks on my table saw using a saw blade, though with a blade designed for clean rips (eg Freud's Glue Line Rip), the marks should be non-existant. I do not like to see any saw marks on the materials I glue-up. I usually use a hand plane to remove them. You could also use a jointer or a jointing set-up on a router table.
Another investment in tools.
To answer your question I am glueing the boards edge to edge to make a wider board.
I like the idea of using a handplane instead of sandpaper. Also I had no clue they desinged a blade specificaly for glue line cuts. With that said I will be buying both a hand plane and and a Freud's Glue Line Rip blade tomorrow.
Second, with my jointer I don't get a clean joint. I get rounded off high marks. What am I doing wrong on that setup?
A little more advice
A couple more things to be aware of:
1) Lower-end hand planes generally require more work to tune up and bring into a good working condition. If your budget doesn't allow a larger investment, I'd recomend picking up an older Stanely handplane.
2) Ralph does make a good point about making square edges, but there are some tricks to overcome that, depending on what thickness your boards are.
I'm not clear on what your jointer is doing. Perhaps a picture of the result would be helpful.
jointers
If your jointer is properly tuned, the knives sharp, and your technique proper, you should end up with almost perfect edges ready to be glued. Jointers will usually, however, leave some "machine marks" - miniscule imperfections in the surface. A pass or two with a (again, properly tuned and sharpened) jointer plane (#7 or #8) will remove the machine marks. The wrinkle is in the hand-plane technique. That is, can you hold the plane as perfectly square to the face of the board as the fence does on the jointer? Thus, in eliminating one imperfection, you might introduce another.
If you start with a sufficient quantity of 1x12s, you can eventually make a table top of perfect 1x2s. ;-)
You might be able to reduce the roughness of the sawn edge using a feather board and removing no more than 1/16" on the last rip.
Some will find it overkill, but after a final skim rip I'll remove the saw marks with the jointer, and remove the jointer marks with a long hand plane. Adds only a few minutes on average, and I think the glue lines are much thinner. Of course, occasionally time is needed to hone the plane's bevel again . . .
Charles:
One more thing to try is to plane both glue-up edges at the same time. Place them both in a vise or some other way of holding the boards side to side, edge up. When you plane this way both edges will be planed the same and should glue-up with minimal visible seam.
It works for me.
Jim
My memory's good, it's just short.
Sawn Edge Only
I will probably be branded as a Phillistine but I join the boards straight off the saw. I have to admit that the sawn edges are off a high quality blade with a finish almost like they have been planed. The glue line is invisible, joining is much quicker without the hassel of trying to get a flat, mating surface and IMO the joint is stronger as the sawn surface which is slightly rougher gives better 'keying', glue penetration and 'more surface area' of glue. The planed surface is almost a polished surface and glue penetration is not as much as with sawn surfaces. It works well for me and is the method I have used successfully for the past 25 of the 50 odd years I have been woodworking.
wot
Glue Lines
Will
Clamp em up tight, scrape em flat, 10 coats of thick black paint, guarenteed invisible.
wot
Glue joint tips from a pretty old guy who doesn't joint or plane
I only glue table sawn surfaces for the simple reason that it is the only way that I can provide "perfectly" parallel surfaces on the edges to be glued. I find that the flat tablesaw top is an easier surface to manage a board on for a square edge than the vertical fence on my jointer. I certainly don't have the skills to hand plane or sand, for that matter, a square edge on a board. My hat is off to those who can!!!
I use a few obvious (after you try them) tricks:
I true up the edges on the table saw with at least a 40T/in carbide combination blade.
When trimming the boards to the desired width, I flip (edge over edge) alternatng boards so that even if the saw blade is not perfectly set at 90 degrees to the table, the joined edges must be parallel. This will be the case even if the blade is purposely tilted to 20 degrees.
I use a smallish quantity of yellow carpenters glue (a skim coat if you will) on only one side. Excess glue simply squeezes out and the boards slide all over during clamp up. If you have large drips, you are using too much.
I wipe the glue off of the top surface with a wet rag to check the joint for tightness. There are those who will say that this will interfere with later staining and finishing, but this is not the case if you truly use a wet rag. Do not do this if you are gluing edging to a plywood veneer panel - the veneer is thin and perhaps porous and wiping will seal the surface.
When clamping, make sure that you see squeeze out all along the joined edges.
I have used this technique on maple, walnut, cherry, mahogany, etc. The only way you will find the glue line is to follow the changes in grain on the adjoining boards. I have many 35 year old, 80" long glue joints in a walnut trundle bed, that can still only be found by an interested woodworker.
An aside - back in the day before I owned a jointer, I trued up the curved edges of rough sawn boards using my table saw with an auxilliary wood fence clamped to the steel fence. I raised the blade up into wood fence making a cove in which the blade turned with perhaps 1/16" peaking out. By passing the bowed edge of a rough sawn board past the blade, you can create a dead straight edge. It is the same principal as a jointer, just a difference in the approach of the cutters to the wood.
Jerry
"using my table saw with an
"using my table saw with an auxilliary wood fence clamped to the steel fence"
Thanks for the tip. This is something I will definitely try.
How do you work around the fact that the infeed and outfeed side of the fence are at the same "level"?
How do you work around the fact that the infeed and outfeed side of the fence are at the same "level"?
The saw blade itself acts as the "outfeed table." The board is still being guided by the pre-blade fence and you have no gravity to push the board closer to the fence after the blade, as you do in a jointer ater the cutter head. If I have a very crooked or bowed (in the plane of the board) board, I draw a straightline onto the board representing the desire straight edge line. This helps identify where I need to work first. Even by taking light removals, you can straighten things up quickly. Sears also sold an aluminum sanding disk to use with this set up. The disk was flat on one side, and had a slight camber to the other side. If you glued sandpaper onto the camber side, and then tilted your blade a few degrees, and let the disk protrude slightly from the cove in the wooden fence, then the board only touched a small area on the disk from edge to center, allowing a very nice sanded edge on a very long board. You did not have to worry about the sanding disk digging in on the input and out put edges.
Jerry
These are things that you learn through necessity, when you have limited space and $$$. :)
Thanks Jerry. The limited $$$ and space applies to me too!
I have had some success with jointing on the router table but this method opens up new possibilities especially as I have a new 1500 Watt 10 inch table saw.
For my dollars, a tablesaw is the best starter tool. It allows you to do so much, in a limited amount of space. It is still the best place I have for flat glue-ups. Also, you can always see the blade. You have to move into the blade, the blade doesn't move into you!! It is also the best disk sander, because of the large flat table. Yes, set up takes a minute, but set ups are always an issue in a small bare bones shop. Have fun!
Jerry
Setup Time
The way I see it, I do woodworking for fun. Therefore the longer it takes the more fun I'm having.
(If I say it often enough I might even believe it)
Charles, this works for me.
Excuse the layout, the comments should be over the pictures - duh.
Larry
picture1 - Jointing red oak with router. Usually use TS if boards over 3' in length.
picture 2 - 4 pieces free standing - no daylight between boards.
picture 3 - Glue up - after about 15 minutes major squeeze out removed with chisel.
picture 4 - Shows scraper parallel to glue line.
picture 5 - Lightly planing out from center.
picture 6 - After planing, removing remaining glue and high spots with scraper.
picture 7 - Sanding with ROS.
picture 8 - Table top cut to size - 18" - using BS.
This forum post is now archived. Commenting has been disabled