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turnerted
4th August 2006, 05:02 PM
Hi
I recently made my first lidded bowl . It was silky oak about 200mm diameter . I had a problem when I attempted to part off the lid section from the blank . I have a 3mm parting tool and tried to keep the parting gap only slightly wider than this but once I got in about 50mm I had problems hanging on to the tool and I ended up using a hand saw to finish off but it was hard work and the parting gap ended up wider than I was aiming for . Are there any tricks to parting off somthing of this diameter ? As it turned out the amount lost in the gap was not noticable because of the pattern in the silky oak but I would like to do better next time when I might be working with timber with a more pronounced grain pattern .

turnerted

rowie
4th August 2006, 07:14 PM
i use a blade from a power hacksaw, only 1mm thick but 12"+long. ground with a single sweeping curve and used like a parting tool.

Tassie Boy
4th August 2006, 07:47 PM
could you post a piccie???

Skew ChiDAMN!!
4th August 2006, 07:58 PM
Yes, there's quite a few! When you're getting into really narrow cuts like that you're battling the laws of nature. :(

For starters, keep the sides of your parting tool shiny clean. Take a few small cuts, then quickly wipe the sides on a good rag or bit of really fime grit s/paper. Really! A mirror finish helps prevent adhesion of gunk, which reduces friction, which... It's a PITA I know, but it works. I know other blokes who wax the sides of theirs, but I find that doesn't really help me. It might work for you, depends on your technique I s'pose. [shrug] I have been known to spray WD-40 on the sides of mine for really cantankerous work, but I don't recommend that unless you A) know what you're doing and B) can get away with a bit of "stain" in the wood. :rolleyes:

Secondly, regardless of width of the parting tool, you should be parting a slot one-and-a-half times that width! Not so important for wider (7-10mm-ish) tools but vital for narrow tools! So, for a 3mm tool you should make a shallow cut, then move it over halfway and cut again, for a total width of 4.5mm. Any tighter and you're practically asking for it to bind.

Thirdly, you could take a file and try tapering both sides of your parting tool slightly so that the bottom edge is thinner than the cutting edge. Again, the idea is to reduce friction by maximising clearance. I'm assuming you're using something with parallel sides, like a BS blade and not a dedicated diamond- or tapered-profile parting tool? {I assume. 'cos AFAIK they don't make those profiles as narrow as 3mm... and I'm not sure I'd trust one if they did!)

Fourthly, mount it in a loooong handle. This won't stop it from binding, but the extra leverage makes it a lot safer. ie. When it grabs, you won't be hit under the chin by a wayward handle. :eek: You'll also find that once it starts binding you'll be able to cut that li'l bit further before extraction/cleaning the slot/polishing the tool sides. ie. less "downtime" during the parting.

There's a few more, but they start getting "techy." Things like "are you parting with a cutting or scraping technique," "filing back the shaft of the tool so the cutting edge is the widest" (I really don't recommend this... what happens once you've sharpened past the thick end, hmmm?) and similar tool-nerd stuff. ;)

Good luck... and where's the photos? :D

Hickory
5th August 2006, 12:43 PM
What they said..... plus, here is a link to how I made a box full of lidded bowls or boxes with simple turning tools and a diamond shaped parting tool. www.msnusers.com/HickoryNeedIsaymore/Documents/Lidded%20Trinket%20Box/Turning%20a%20wood%20trinket%20Box%2Edoc?t=7XNF3tfoDFVNRjNb*U6rXW10kzbp6JpIqGDc0eDAuympHyJnr1ghkCWHGUZJ1dBeDSMRWBDzsJiSjVE!69C50zQENXCS97!pTcN2iSb8c736L0KSU39APCdudxBwEnvv5zdrDZuIKEnbY$&p=7Mu9IY6l1D*1FGY*6qEpWwoPVd*IIkKVnDvtsaJKIMAJA2DV1WueQiAV3RzYsTzluXPlZALal5EUwIuCL17999nytXN4*Tya3hsq*9maaZF*A!jKWwEE7ppMctz19TlFhBJkL!zi6fS!FIfn7b8BljR2!ixU!KWUwbTd!sv4q8TS0$ (http://www.msnusers.com/HickoryNeedIsaymore/Documents/Lidded%20Trinket%20Box/Turning%20a%20wood%20trinket%20Box%2Edoc?t=7XNF3tfoDFVNRjNb*U6rXW10kzbp6JpIqGDc0eDAuympHyJnr1ghkCWHGUZJ1dBeDSMRWBDzsJiSjVE!69C50zQENXCS97!pTcN2iSb8c736L0KSU39APCdudxBwEnvv5zdrDZuIKEnbY$&p=7Mu9IY6l1D*1FGY*6qEpWwoPVd*IIkKVnDvtsaJKIMAJA2DV1WueQiAV3RzYsTzluXPlZALal5EUwIuCL17999nytXN4*Tya3hsq*9maaZF*A!jKWwEE7ppMctz19TlFhBJkL!zi6fS!FIfn7b8BljR2!ixU!KWUwbTd!sv4q8TS0$)

Sorry I don't know how to make a neat link thingy.... :o

I sent this to a gal in London who was trying to find project for a hands-on school for problem students. She said it was a hit with the kids and they made a multitude of them.

turnerted
6th August 2006, 06:58 PM
Thanks for the suggestions .
As for the pickies , I have first to master my wifes digital camera and then learn how to post pictures .

turnerted

rsser
6th August 2006, 07:01 PM
I've not tried a 100mm cut with a parting tool ... reckon it would be exciting to say the least.

Of course you're wanting to match the grain as closely as you can btwn top and base so you want the least waste. Skew's advice in this respect as in most is wise.

For myself I wouldn't be too fussed about going as deep as I could with what I have and finishing off with a tenon saw or the like ... if that's what it takes to minimise waste.

Hickory ... was interested in your link for more reasons than the technical, but not being a member, nor wanting to be, of MSN groups, have had to forego the pleasure.

rowie
10th August 2006, 08:08 PM
Thanks for the suggestions .
As for the pickies , I have first to master my wifes digital camera and then learn how to post pictures .

turnerted
yeah, me too:mad:

rowie
10th August 2006, 08:22 PM
could you post a piccie???
sorry mate:( the blade is from one of those machines that look like a big hacksaw used to cut metal to length.:confused: its about 350mm long, 40mm wide, 1mm thick. i have ground all the teeth off and just wrapped the end up with thick tape as a handle. works just fine. cutting edge is curved like the top half of a normal diamond point tool.