Tight Fitting Miters

dusty · Post by **dusty** » Tue Dec 06, 2011 5:52 pm

We have just been shown some really nice mitered corners on some equally nice picture frames by undergrub.

I thought that as a result of this show of experience here, we might be able to get some discussion going on what must be done to achieve tight fitting joints like these.

Four, six or eight sides or whatever.

Mine are not prize winners so I'll probably not show any of them. What I will say is that since I got my Incra V120 Miter Gauge and my Wixey, I do get some better fitting joints.

However, these normally do not come without some extra sanding using the same Miter Gauge and the Shopsmith Sanding Disk.

fjimp · Post by **fjimp** » Tue Dec 06, 2011 7:26 pm

For me the best joint accuracy occurs when I use the Shopsmith/Incra 5000. I have the V120 and use it frequently for crosscutting smaller piece work. Yet when I desire extreme accuracy the 5000 comes out every time. Fjimp

algale · Post by **algale** » Tue Dec 06, 2011 7:27 pm

Best tool for that is the original Lion Miter Trimmer by Pootatuck (not sure whether this is still made). That's what we used in the framing shop at the Hood Museum of Art; I inherited one from my Grandfather which his company, the Old Colony Furniture Co used to trim mouldings.

Al

Al

pennview · Post by **pennview** » Tue Dec 06, 2011 7:29 pm

Undergrub pointed out the key to good miters -- opposite sides must be identical in length and the miters must be exactly 45 degrees for a four sided frame. You get the identical length by using a stop block on your miter gauge fence/extension if you're cutting with a table saw. Getting the angle correct is a matter of set-up.

As I mentioned earlier in a separate thread, I use a scrap frame and make test cuts until the angle is exactly 45 degrees. This means trimming the end of each piece in the frame for a total of eight cuts. If the angle isn't right, tweak the miter gauge and then make eight additional cuts until the angle is perfect.

I number the four sides of the test frame. Set the stop block to trim a small amount off of one end of each frame part, adjust the stop block, and cut the opposite ends of the four parts. The numbering of the parts keeps from making mistakes. After making all the cuts, I lay out the parts in sequential order and use masking tape to hold the pieces together and then fold the parts together to make a square. If the joints don't look good, it's back to tweaking the miter gauge angle and then making another eight test cuts.

I do the same procedure for tilting the saw blade on my table saw when making boxes with mitered sides. I don't use the Shopsmith by tilting the table because I don't like the little offcuts flying around the shop.

When I use up the test frame, I simply make another one. Using pieces about 2" wide makes judging the accuracy of the miters relatively easy.

beeg · Post by **beeg** » Tue Dec 06, 2011 8:40 pm

[quote="algale"]Best tool for that is the original Lion Miter Trimmer by Pootatuck (not sure whether this is still made). That's what we used in the framing shop at the Hood Museum of Art]

http://www.lionmitertrimmer.com/

algale · Post by **algale** » Tue Dec 06, 2011 10:12 pm

beeg wrote:http://www.lionmitertrimmer.com/

That's the tool, alright, but when you click the links for where to buy online, the links are all dead and right-tool's site says the product is no longer available. Makes me think they are kaput. Too bad.

Hard to explain how effortlessly this tool could cut paper thin shavings off of quite large hardwood mouldings.

rpd · Post by **rpd** » Wed Dec 07, 2011 4:17 am

Lee Valley still lists that looks very similar

http://www.leevalley.com/US/wood/page.aspx?p=32922&cat=1,42884

foxtrapper · Post by **foxtrapper** » Wed Dec 07, 2011 5:59 am

I hope it's an illusion in the picture, but the tool on Lee Valley's page looks like it's got a blade bevel away from the table. That would make it work about as well as a pair of scissors sharpened on the inside of the blades.

Gene Howe · Post by **Gene Howe** » Wed Dec 07, 2011 8:27 am

I used to own a Lion Miter. Great little tool.
When I got the Miterset and used it a few times, I sold the Lion miter.
BTW, the Kreg miter gauge helps, too. Too bad they won't adapt it to the SS any longer.

algale · Post by **algale** » Wed Dec 07, 2011 8:35 am

Gene Howe wrote:I used to own a Lion Miter. Great little tool.
When I got the Miterset and used it a few times, I sold the Lion miter.
BTW, the Kreg miter gauge helps, too. Too bad they won't adapt it to the SS any longer.

That's a nice looking accessory. Do you find that you can get as cleans cut with a table saw as with the Lion Miter? In my experience, even when used in conjunction with a zero clearance insert and backer, I couldn't get as cleans cut as with a well honed Lion Miter.