Turning tulipwood

[GrahamRounce]

It was really hard (impossible for me, to be honest) to get the end-grain smooth. The fibres seem to lay down like a field of wheat. Even after I managed to sand it more-or-less ok, you should have seen the mess after I stained it! Every microscopic blemish, and every macroscopic one too, of which there were plenty...

Funnily enough, though, the sanding disc does a perfect job. But you can't finish a bowl on a sanding disc. Is there another technique I should know about? (Apart from sharpening the chisel every 10 seconds?)

Graham

 

[stevebuk]

apparently have razor sharp tools and take light cuts, but i have never turned tulipwood.

 

[Bodrighy]

I
Funnily enough, though, the sanding disc does a perfect job. But you can't finish a bowl on a sanding disc.
Graham

Who told you that? Smetimes, if the bowl s worth it you can an do. Don't think for one moment that we all get a perfect finish with out super saharp tools all the time 'cos we don't :lol:

Pete

 

[CHJ]

..... Is there another technique I should know about? .....

Practice and patience, lots of it, resist the temptation to use expensive woods for a while, although the bigger variety of species you try the better your appreciation of turning characteristics will be and a knowledge of which ones are just not worth the effort, by the time you are knocking out your 50 or 60th item you should have developed some answers to your questions.

 

[jasonB]

I assume you are talking the relatively cheap tulipwood (N A Poplar) not the exotic hardwood. The problem with the former is it is very open grained and relatively soft so you need a good sharp tool to cut the fibres, anything else will just bend them over as you have found.

Jason

 

[GrahamRounce]

Hi, and thanks for all the replies. I was disappointed, though, to still not learn the secret of quick-and-easy masterpiece-making...

"by the time you are knocking out your 50 or 60th item" !! I was reluctantly starting to pin my deferred hopes on the 3rd or 4th!
I'm joking, of course. Just that not being in the first flush of youth any more, anything less than warp factor 20 seems wasteful...

Ok, I accept all that advice, but I'm still puzzled as to WHY the sanding disc (coarse grit) gives such a superb marble-like finish on the end grain, with just some light striations to be smoothed out, and the opposite, namely moving workpiece and stationary abrasive, errr doesn't!?

Thanks,

 

[Bodrighy]

Could be because the sanding disc sands in the opposite direction to when the wood is mocving and the abrasive is stationary? Lathes with reverse motors apparently have the same effect

Pete

 

[GrahamRounce]

Hmmm.... ok, but I'm not convinced. I bet if I turned the wood over before presenting it to the disc it'd get just as good a finish... I think it's something to do with the solidity of the connection between wood & abrasive: Using the disc, the abrasive paper can't really move backwards, and the connection is continuous. The other way, the paper is pretty free to move, and if the workpiece isn't exactly circular the contact will vary... *Maybe*...! ...Can you get fixed chisel-holders, like on a metalworking lathe, to help you get an exact continuous circle? That would help, I'm sure, but I'm only guessing.....

 

[CHJ]

My thoughts on the matter are that the friction drive rotary sanding discs if used lightly result in a multiplicity of grit directions at any given point on the surface, going down through the grades results in shallower and tighter random direction scratches that are very short in length even to the point that the eye does not perceive them.
The chances of rogue grain being cut by the abrasive crossing it in a different direction to the lathe tool are high.

Hand sanding with the lathe rotating results in concentric scratches that are quite long, even if circular hand motion is used, these are easier for the eye to register.
The abrasive is cutting in the same direction as the tool so is just acting as a much finer tool.

It is not unusual to spend as much time hand sanding in the direction of the grain with the lathe stationary or with the piece off the lathe.

 

[GrahamRounce]

Hi - Sorry for not making it clear that the sanding disc I'm talking about is one on the lathe, like this:

(incidentally, the paper is held on with double-sided sticky, which works well and is muy economical).
Anyway, even with 40-grit it turns this from the bandsaw...

into this...

(which is much better, even if you can't see it very well)

I might be wrong, but were some people talking about power-sanding sanding the workpiece on the lathe with a sanding disc on an electric drill? I haven't tried that yet. What kind of a finish does that give? A bit noisy & dusty I bet!

 

[CHJ]

Graham, I was referring to using a friction drive sanding tool, although the same applies to a drill mounted one but that tends to be as you say much dustier due to drill fan spreading dust and can be more aggressive.

See these threads for details of some models and their respective merits.

https://www.ukworkshop.co.uk/forums/viewtopic.php?p=75861#75861

https://www.ukworkshop.co.uk/forums/viewtopic.php?p=383451#383451

 

[Vulthoom]

Graham,

I had a similar problem with my first two attempts at Tulipwood (Poplar).
The wood was white and rather soft and fibrous and I found it almost impossible to get a decent finish.
As others have mentioned, this is also due to my lack of finesse...you can probably turn balsa if your tools are sharp enough.

The white sapwood seems to get very soft towards the edge of the tree - the third
blank I tried had some of the olive green heartwood outcropping on the surface and when this was turned it produced a very nice bowl.
The heartwood is a lot denser, a very attractive dark olive green and took a much better finish, even the sapwood areas.

So I suppose if you can pick and choose, go for blanks which have at least some heartwood showing..?

 

[Bodrighy]

I was giving some offcuts by someone who makes rocking chairs and must say I didn't rally find it a problem though I have turned quite a bit of pine so perhaps I am more used to this sort of wood. Only difficulty ws I found power sanding was too aggresive as it strippped the wood away from any edges that you wanted to keep sharp

Pete

 

[Paul.J]

Bodrighy wrote

I was giving some offcuts by someone who makes rocking chairs

You were also given some by someone who makes Rocking Horses :lol:
Never tried turning it meself but it does carve nice,even on the end grain so long as the tool is sharp

 

[Bodrighy]

Bodrighy wrote

I was giving some offcuts by someone who makes rocking chairs

You were also given some by someone who makes Rocking Horses :lol:
Never tried turning it meself but it does carve nice,even on the end grain so long as the tool is sharp

Picky picky :lol:

Pete