Boring Bar Help

[Growley]

Hey guys,

I need some help finding a boring bar.

The problem: I've got a customer that wants a pipe with an oversized chamber. I've never had any luck re-profiling spade bits for the task, so I thought I'd try drilling a 3/4" hole with my good bit and boring it out to the required size. So I have three questions:

1. Does this seem like a decent idea?
2. What boring bar will work well for this?
3. Let's say I wanted to just spend some money and get the "perfect" pipe makers bits. What would you recommend? I bought some which were supposed to be good when I first started, but they were admittedly dull, and I can't seem to get them sharp for the life of me.

Thanks for any help you can offer.

Brian.

[e Markle]

I did that once, but I used a plain old boring bar - no special profile. After that I just glued some 100 grit to the bottom of a dowel rod to make a uniform curve at the bottom.

If you don't have a boring bar, I'd be happy to send you one (I bought a set, and don't need that many); just PM me your address. Just don't forget you need a certain kind of tool holder for it if you have a QCTP.

[Growley]

I did that once, but I used a plain old boring bar - no special profile. After that I just glued some 100 grit to the bottom of a dowel rod to make a uniform curve at the bottom.

If you don't have a boring bar, I'd be happy to send you one (I bought a set, and don't need that many); just PM me your address. Just don't forget you need a certain kind of tool holder for it if you have a QCTP.

PM'd... Thanks Ernie.

I'm still interested in hearing what you guys think for good drill bits too...Spade?, Spoon? Standard? I'm just drilling on my lathe, no free hand stuff.

[taharris]

Honestly, it's not that hard to profile your own spade bits.

Just take a spade bit of the diameter you need, draw the profile you want on the bit with a sharpie and then grind the profile you want.

When you are done put a bevel on the edge on the left side and then turn the bit over and put a bevel on the other left side.
(Much like sharpening a scraper)

Or, just tell me what size and profile you want and I will grind one for you.

Todd

[Sasquatch]

I re-bore pipes all the time with a small parting tool. This is a plain tool rest and tool-in hand operation. It is easy. Then the chamber can be whatever shape you want. This can be done with a gouge too.



We are turning.... bowls, after all, so bowl turning techniques work. Just... small.

[Growley]

Define small... I think mine would be too large. Do you mind uploading a pic?

Thanks for the thought!

[Sasquatch]

I use these a lot:

http://www.leevalley.com/US/wood/page.a ... ,330,43164



They is good.

[Growley]

I use these a lot:

http://www.leevalley.com/US/wood/page.a ... ,330,43164



They is good.

Thanks SAS. Mine are much larger than those. I just ordered a set, not those exact ones, but similar.

[Sasquatch]

Yeah there's other good small tools around, I've seen a few top-quality ones at woodworking supply stores.

I do a lot with the skew, the 1/4" gouge and the parting tool.

[smokindawg]

Well, after looking at that mini HSS set I had to have one. I now have one on the way. Bought it on the bay for $36 shipped.

[Growley]

Yeah there's other good small tools around, I've seen a few top-quality ones at woodworking supply stores.

I do a lot with the skew, the 1/4" gouge and the parting tool.

Sas,
I started messing around with turning a chamber this way last night, and I couldn't tell if it worked better on the push or the pull. Do start from the inside of the chamber and cut on the pull, or do you start on the outside and cut on the push?

[Sasquatch]

I start at the rim and push in. Basically I drill the hole as I normally would, or maybe halfway for depth or whatever (I seldom drill to completion on the lathe). Then I just open it up by sliding the parting tool in and just cutting along that inside wall.

The wickedest part of this is that if you do open it up a bit, you can drill the rest of the chamber at a different angle (sometimes handy in bulldogs for example).

[PremalChheda]

You can make a dowel rod with a slit down the middle to hold 80 grit sandpaper and sand the bowl to the desired size. A spade bit will work much better.