Cedar of Lebanon Board

[Chris152]

(Don't worry, I'll just post the outcomes together at the end of this one...)

Tears out easily, doesn't it? Anyway, I just cut a bit off the top right limb to see how it turns.

It looks lovely and glossy til I turn it to the light. Do you think the lines are sandpaper on wood or on the shellac sanding sealer I used? The photo does a good job of emphasising them, but they're clearly there when you hold it to the light. I used to 400 grit on the wood and 800 grit hermes paper to de-nib the sealer. Any advice on how to improve it greatly appreciated!

Thanks

C

ps I'm doing the things you've advised to reduce sanding marks in the wood, so hoping the answer's in the sealer!

 

[CHJ]

I think you are seeing the results of sealer applied with the lathe rotating.

A few pointers,
Seal surface before final cuts to reduce tearing soft grain.
Make sure you sand through the grits and remove previous grit grade scratches, again applying sanding sealer or just water will enhance scratches and show them up.
Do final sanding with the piece stationary and sand by hand with the grain.

Apply your final sanding sealer by hand with the item stationary, again with the grain or small circular motions, not with the lathe rotating.

For the current item, take some 240-320 grit and sand the item with the item stationary and with the grain, apply sealer and check for scratches, they will still be there but more than likely invisible to the eye.

 

[Chris152]

I applied the sealer with the bowl static, so I don't think it's the application that's the issue Chas.
And I tend to apply in circular motions, so I guess that's not it.
What is best for sanding back the sanding sealer? As I did this one, I felt that the hermes paper (which is self adhesive and I bought for plane sharpening) was too stiff. I've used 00-000 wire wool before with better results. Could that be it? The Chestnut videos you linked to in other threads shows use of that scouring pad stuff - should I try that? If so, which grit would you suggest?

Many thanks

C

 

[CHJ]

You say you are using Shellac sanding sealer, how thick are you applying it?

Make sure you are not building up a thick coating, in effect applying it as a polish, it tends to be pretty soft when first applied and easy to get build streaks unless you've mastered the art of friction polishing.

Looking again at your image the lines are certainly concentric so have been formed when the piece was being rotated either with initial sanding scratches that have not been removed or during polishing that has tramlined the shellac or applied polish.

Normally a light sanding with minimum pressure with the last grit grade you used is adequate to de-nib and clean off any dust motes you have collected.

The Nyweb grades are:-
The Green 400 grit
The Red 600 grit
The 1000 grit
The White pads do not contain an abrasive.

But personally I'd be surprized if you get any visual benefit with a soft Cedar by going to such grades.


I reiterate, try sanding with the grain by hand and see what it looks like. 320 grit should be fine enough.

 

[Dalboy]

As already stated work through the grits if you sand with the lathe rotating then stop after each grit and hand sand with the lathe stopped and with the grain until all signs of the scratches from the previous grits have disappeared it can take a bit of time but well worth it in the end

 

[Chris152]

Thanks fellas. Before I go any further I'm going to cut some simple discs from scraps and experiment with different techniques for sanding the wood and sealer. I ordered some nyweb which should arrive tomorrow. Also, I think I need more practice with the power sanding set disc that i got recently - there's clearly a fair bit of technique to getting that working right? Also, it's possible I've been applying the sealer to thick Chas - I'll try adjusting that.

Thanks again

C

 

[Chris152]

Quick update. Two things:

1. I was lucky to be able to watch Paul Hannaby turn the inside of a bowl at Cardiff Axminster on Saturday. Among other things, he said to keep moving the sandpaper across the direction it's turning in order to avoid scratch marks. I've tried that and it works really well combined with other advice I had in my 'scratching' thread.

2. I turned a larger bowl from the Cedar. It really wants to tear out to the point that it's hard to make proper cuts with the gouge, I found. I even resharpened to 240 grit but still a struggle even with fine cuts. More of a problem is that I just put a coat of boiled linseed oil on and, in spite of the really nice grain, it now looks like a piece of recycled 70s kitchen furniture. Blahhh.

 

[CHJ]

Nothing wrong with that figuring, it's what nature intended.

What you perceive as an improvement on nature may not be what others regard as such.

 

[Chris152]

I did this one today, I decided I wanted to make something that might actually be useful.

It's finished with walnut oil, which I quite like.

BUT - a funny thing happened. As I was turning the inside, the lathe tripped the fuse box thing. I reset it and started the lathe again - fine til it reached a higher speed when it tripped again. This happened a few more times so I left it alone, came back after 20 mins and all was fine - and subsequently used the extractor on the same extension (as usual) and all was fine. Any idea why this might have happened? The only thing that's different today is that it's quite hot (air temp, I mean - the motor was just a bit warm to the touch).

edit - I'll ask this one in the general part of the forum - I'm slightly anxious about it and it'd be good to get an answer before I use the lathe next. I don't have a clue about electrics and as far as I know it could be anything. :?
C