Using a pre-fabbed baffle - how do I get 90* corners so it fits properly?

Use a chisel.

These days guys don't think about using hand tools; give them a chisel and many would be puzzled as to where to find the 'on/off' switch.

Despite having over 50K in woodworking machines for that job I would reach for a chisel, more specifically a corner chisel. To do a "perfect" job without a corner chisel (which I assume you do not have) you need a SHARP chisel (bench or paring it doesn't matter). The problem is most woodworkers don't have a good chisel and almost never have a sharp one. A well sharpened chisel with a micro-bevel will cut paper like a razor blade but most woodworkers with a bent toward hand tools (I do both) will have hundreds of dollars invested in sharpening implements alone. I say all this to make a wild guess you may not have a proper chisel available, even buying a (good) chisel would not work since it will need to be lapped, sharpened and honed. The best solution is a flat "chisel" Xacto blade and taking your time. Score the wood first so you are less likely to have tear out and take your time and you can get a nice near perfect corner. The best blade would be an Xacto #18 but a #17 would work in a pinch.

And how in the heck do I get the bit out of this wooden chuck?

Or wonder where the battery charger was since without a cord it must be battery powered...

I am a big fan of Lie-Nielsen hand tools. There are also some quality chisels available from Lee Valley, but I don't have much personal experience with them.

That being said, learn to sharpen your blades and a package of Stanley chisels from the local hardware store will do the job quite well, although you may need to hone them more often.

When you put it that way, I've got to wonder why you wouldn't just round the corners of the baffle.

I'd probably still reach for a chisel to do that. Setting up a jig to round the corners with a router would probably take me longer than doing it by hand unless it was a big production run.

I am confused about this.....Is the original problem that the edges of the (pre-fab) baffle are but at angles, ie similar to what you would cut into a piece of crown molding with a miter saw? If so, would you not just run the boards for the top/bottom & sides through a table saw set to an angle that matches up with the baffle? Is a chisel really capible of cutting a precise angle like this? If so, any tips on how to do it correctly? (I am a total newbe and apologize if these are stupid questions).

You guys are over thinking this. It's all going to be covered by the baffle if I understand the OP correctly. So you have options: hack out the 90 w/ a chisel, knock off the corners of the baffle at a 45 w/ a chisel, or drill the box at each dashed line intersection with a 1/4" bit.

I use this to sharpen chisels:

http://www.amazon.com/DMT-D6FC-6-Inch-Dia-Sharp-Double-Sided/dp/B000GD8WHY/ref=sr_1_27?ie=UTF8&qid=1358949350&sr=8-27&keywords=dmt+diamond+sharpening+stone

This is my chisel set:

http://www.homedepot.com/h_d1/N-5yc1v/R-100067444/h_d2/ProductDisplay?catalogId=10053&langId=-1&keyword=chisel&storeId=10051#.UP_sMB3nXSg

Think about the simplest case of this, which is a stopped dado for a shelf.

If you use a router to cut the dado, at the end of its travel it will leave a semi-circular end, that is the nature of using a round bit.

So your shelf, which is squared off, won't slide all the way forward, and there will be a big ugly gap in the side just in front of the shelf.

Your options in that case are:

• Use a mortising tool or chisel of some sort to square the end of the dado
• Use a router or chisel to round off the end of the shelf
• Use a saw or router to notch the shelf so it can be slid forward further

This case is similar to that, in that a channel is being routed, and the 90 degree turns are only sharp on the inside, not the outside. The panels intended to fit into them will interfere.

I was thinking about this earlier and it hit me their is a cheaper corner chisel. Whiteside makes an excellent small corner chisel that would work well in this senario, should run $20 or so. You will still need to use a chisel or similar implement to cut the waste out from the bottom.

As for chisels in general I have used them all, from Blue Spruce to Harbor Freight specials, save the new Lee Valley PM versions. Lie Nielson makes an excellent chisel and even at their price I suggest them to new hand tool workers since they come ready to use out of the box. If you don't have a mentor it is hard to know what a good chisel can do until you have had one in your hands. That said most people, even long time woodworkers don't want to pop for Blue Spruce or LN chisels. By far the best value in western chisels are Narex, Highland and Lee Valley both sell them but I would go with the imperial bench chisels from Lee Valley (Highland only has the metric last time I checked). That and one of the sharpening kits from Lee Valley (I would go with the one with the Veritas MkII jig) and one can do a lot. If you want to save even more money on sharpening google scary sharp and look at the sandpaper sharpening approach. On my point about imperial bench chisels vs metric, with a bench chisel it makes no difference really but with the option I tend to go with imperial.

Sorby and LN sell good corner chisels but the Whiteside would be the cheapest way to have a corner chisel that would work well here. If you decide on one of these small corner chisels do NOT get one of the cheaper versions like Porter Cable and Grizzly sell both are garbage IMHO.

Even the most ardent power tool woodworker needs some good handtools, the three essentials that pop to mind are a small set (4) bench chisels, scrapers and a high angle block plane. I do caution as handtools can be a vortex for money, the next thing you know you will have 20 hand planes, a wall full of saws, 30+ chisels and be arguing over oil stones, water stones and diamond stones... You know you are completely off the deep end when you have a 2 and three jaw brace, actually use gimlets, start a rounds and hollows collection and start thinking of taking out a second mortgage to have Karl Holtey build you a custom infill plane... http://www.holteyplanes.com/


One other thought if you happen to have access to a square chisel mortiser you can use that to square the edges. Ha I figured out a way to use a power tool after all.

Ok, this just confused me like a trillion times more, but, I appreciate you taking the time to try and help me! LoL. What is a dado? What are you referring to as the shelf? I have never really used a router, so I am not sure what is "at the end of its travel". Also, what do you mean by "square the end of the dado"? Please bear with me as I am a total woodworking newbe, but with that being said, I am also very serious about learning how to do this stuff. Any further attempts to educate me would also be greatly appreciated! Thanks!

A dado is a square-bottomed groove cut into a piece of wood. Here's an article all about making dadoes with a router. The referenced article will tell you more than I can and has pictures, too.

Thanks JD! That was a great instructional. I will definitely be building a dual fence jig.