Why a joiner?

[lcm1947]

This may be the dumbest question yet but here goes. [B)] I just flat don't understand why a joiner is needed although I am well aware that everybody has one so they must be needed but I just can't figure out where. Are they just used to sand the side edges of boards and that's the deal? Do they make both edges parallel also and if that's the case why weren't the boards ripped parallel in the first place? I could go on and on but don't want to embarrass myself further so would some kind soul enlighten me. [:I]

[LCHIEN]

First of all you need to know that there's a tool called a joiner and a tool called a jointer and they are frequently confused.

The tool I believe you are referring to is a jointer with a T
and is used to make a flat face and or a flat edge on a board.

The tool typically has a long straight and flat, solid, ridgid bed, usually 40-50 inches and in some cases 60-70" long and the main purpose of this is to make the face of the workpiece straight over a long length as required for joining them into a wider panel for example.

Using a sander removes material at a local spot and does not guarantee that it will be in line with the other 7 feet of the board. The long bed is the key reference in a jointer.

The jointer is also usually 6-8 inches wide allowing it to put a flat face on a board, the long bed again assuring that the face is not twisted and or warped.

The Joiner tool (no "T") is a tool that places special joinery cuts into two pieces of wood that are to be joined together. The classic one is a plate joiner or biscuit joiner designed for making fast and accurate edge joins for panels.

For making parallel edges on a board, use a table saw after only making one edge perfectly straight with a jointer.

For making parallel flat faces, use a thickness planer after
planing one face of a board perfectly flat on a jointer.

[boblon]

Well, I may not get all this right, but I'm sure someone else will add to this thread.

First I'm assuming you mean a jointer. Most folks that have one have a 6" (but wish they had the money, room, or both for a larger one). It is used to flatten first the face of a board and then to square one edge up to that face. This provides a true 90 degree corner to work off of.

They can be used to create a rabbet, or an angled edge also, but I don't think most are used for that.

To create the opposite parallel face the board is run through a thickness planer. And to create the opposite parallel edge, the jointed edge is place against the fence of a table saw and ripped to size.

I hope this is understandable. Anyhow, the reasons you would want to do all this is very few boards (even S4S's) end up truly square by the time you go to work with them. Especially ones from the Borg's out there.

You can use an accurate table saw, like the Bt3's with a good blade to get a glueable edge on a board, but if the wood is cupped or mishapen along it's face, that's a different situation.

You can use a sled with just a planer to get one face flat, although I've never tried that, but a jointer is really the right tool, as long as the jointer will handle the width of the stock your working with.

Another reason to have a jointer and planer is so that you can work with rough stock. Also, your choice of wood is greatly expanded as your not relegated to what is available at the big box stores. (You can have your hardwood supplier mill it for you if your working on a specific project and have a good plan and cut list). I like to keep some rough stock on hand for use when the urge strikes. This wood is usually less expensive by the board foot. This is the real reason I got my jointer/planer. There is just something magic about taking some butt ugly looking piece of lumber and milling it into usable stock, then making something beautiful out of it.

This is a post of my first little project doing so:

http://www.bt3central.com/forum/topi...TOPIC_ID=20221

There's a pic of the wood I started with, and the box I made out of it.

I am no craftsman (yet), nor an expert by any means and I hope if I've missed the mark here, someone will corect me.

BobL.

[lcm1947]

Thanks guys excellent replies but still a little confused. Sorry. You were right Loring I meant a jointer, thanks. Now assuming I am correct and that face means the wide part of a board and edge of course would mean the narrow edge then a jointer actually flatens the board face ( wide part ) and also insures that one edge is true or straight and 90 degrees to the face? Is this correct? And if this is correct I don't see how a jointer could make a board flat since there's no reference point. Now a planer I can understand and see how that works but the jointer, well I just still don't get it. So you are saying that the face and edges are both straightened by the jointer? I must be missing something here or just plain stupid and after two very detailed replies too. [:I] I know it's me but would really like to understand.

[LCHIEN]

Yes, as Bob correctly stated, it would put a 90° alignment to the face and edge (or any two adjacent sides e.g. for a square post) if the fence was aligned so.

You have to look at the way the jointer is constructed. The blade and the outfeed table are level, the infeed is in a parallel plane but lower by what you set.
As you feed the material everything below the outfeed table surface is cut off.
If it touched at three or more places on the infeed it'll be flat on the outfeed, simply put.

[Hoover]

I'll give it a go. The jointer itself is the reference point. The wood passes over the blades removing the high points of the lumber in each pass. As each pass over the blades more wood is removed, until the face of the board has an even amount of wood removed resulting in a flat continuous surface. This is then your new reference point for the board.

[boblon]

Here's a quick pic trying to show what the two posts above are describing. (Not to scale or anything of course.)





Hopefully this will help (I'm no artist either !)

BobL.

[LCHIEN]

quote:Originally posted by boblon

Here's a quick pic trying to show what the two posts above are describing. (Not to scale or anything of course.)





Hopefully this will help (I'm no artist either !)

BobL.

Good Illustration, Bob.

[Pappy]

The reason a jointer is necessary is as stated above. Running a twisted, bowed or warped board thru a planer will produce smooth surfaces, but it will still be twisted, bowed or warped...just thinner. By getting one face and edge flat and straight on a jointer, the planer and table saw can take care of the other 2.

[gonesailing]

Might want to add that flattening the face is the first step and may take several passes through the jointer.

The the board is set on edge and the same prcess is used to "flatten" it.

The jointer has a bed, where the cutting head is (good diagram above) and it also has a fence which keeps the board at right angles to the bed, or at whatever angle you set it at.

It is amazing to me that I have such difficulty describing something so simple [)]. A picture would probably clear things up quickly.

Mike

[lcm1947]

What's that old saying " A picture is worth a thousand words '. Boy is that true. That picture did it for me. Thanks boblon for thinking about doing that and taking the time to bother and thank all you for helping. Although you see some of the problem was that I never visalized a board not being flat in the first place or at least not pretty darn flat so I couldn't see the need to do that unless of course it was in bad shape. What a neat idea the jointer but don't see the need at this point for myself since my near future involves cabinets. To learn all the different phases of woodworking I've decided to replace all 5 of my 2x4 tool tables with cabinet type tables in an effort to learn how to use all the different tools such as screw pockets, biscuit joiner, router and of course the big tools like TS,DP and BS. I also want to learn how to do glueing although that sounds like a pain. Anyway, thanks a million you guys. I really do appreciate you all and this forum.

[monte]

Bob and Loring have covered it really well. My jointer is probably the next most used tool in my shop after my BT.

[LCHIEN]

quote:Originally posted by lcm1947

...Although you see some of the problem was that I never visalized a board not being flat in the first place or at least not pretty darn flat so I couldn't see the need to do that unless of course it was in bad shape. ...

Just go take a look at Lowes or Home Depot in the
so called white-wood dept where they have the 1x4's and 1 x 6's
(not the Oak and poplar section). Pick a few boards and sight down them, you'll see what "not flat" means.

[final_t]

I fully recommend this book for pretty much anyone, new or old:

The Complete Manual of Woodworking, Jackson et all.
ISBN 0-679-76611-1
$16.50 at Amazon. (How do I link it so Sam gets his cut?)

In any case, it has pictures, examples, all sorts of this-is-how-it-works and stuff. ****, just a good read even for old farts like Loring I like the section on joinery myself.

I really need to get off my arse and get the wiki updated with some bookage.

[lcm1947]

Now that you mentioned it Loring I'm probably just not that aware of 1x's and such since so far I've just worked with sheets goods and 2x4's. I guess I always just assumed 1x's ( boards ) was quality stuff. Thanks final t for the recommendation about the book. Not that I really need it but I'll take a look at it.