Advice for a newbie.

[kirso]

Hello,
My apologies to all who read this and think " does he not know that". But no I don't but hopefully I will when I receive some replies.
The problem is. I Have just been turning my first ever largish bowl (9ins) {insert smutty jokes here}.
And hopefully you will see in the attached pics that there are 2 areas I am unable to get flat with sanding. I tried all sorts of grit specs and no matter what I did there was always these small areas of what looks like breakout of wood. I don't know the correct terminology for it . But it aint smooth..
I suspect it is something to do with the grain direction and the rotation of the lathe. But it is guess work at my end.
Hopefully some one will enlighten me on what it is , and hopefully how to get it smooth.
Thanks

 

[CHJ]

Areas of rogue grain like that are not uncommon, sometimes it is all down to the wood growth itself but more often it is just being difficult due to less than perfect cutting technique.

If your tools are not the sharpest possible, and sometimes even if they are, the tool drags on the fibres and pulls them instead of slicing off cleanly. try to make sure you are slicing with the cutting edge as opposed to chopping, think of the difference between sharpening a pencil with a pocket knife and the difficulty of trying to cut the pencil in half with the same knife.

This 'pulling' of the fibres can go several millimetres deep once created and be difficult to disguise.
Try soaking the area in sanding sealer or if you intended finish is oil use that before continuing with the cutting or sanding.

The former, sealer, will swell the fibres and give them support whilst cutting, the oil will just swell them and help with the cutting.

Next time you see these areas forming soak the area in sealer, oil or water before final cuts with freshly sharpened tool.

 

[kirso]

Thanks for the reply.
Do you have any recommendations for sealer ?
Will one type work on all woods ?
I have ordered some mineral oil for bowls etc used with food. So will try that next time.
Most stuff upto now has had a coat of Danish oil then bees wax. But this has been put on at the very end. So I will cover the areas prior to final cut if I have the issue again.
Thanks

 

[CHJ]

If you want to finish off with a wax the simplest sanding sealer is Cellulose, easy to apply and very quick drying, seconds. See this short vid
Shellac sealer being spirit passed is slower drying and not quite so 'hard', minutes.
Acrylic sealer because it is water based is slower drying but very tough once fully cured.

Don't apply any sealers if you intend to use a finishing oil, they will prevent oil penetration at best, leave you with a very blotchy finish at worst due to uneven penetration.

Food safe mineral oil is only a water repellent oil, ideal for salad bowls that are to be wiped with a damp wipe or quickly swilled under cold water, never use soap or detergent to clean it will rapidly remove the oil. It will not polymerise and form a sealed skin. Won't stop an applied wax penetrating the wood and may produce a blotchy look if you do.

99% of my pieces are finished with Cellulose Sanding sealer and a hard wax such as Carnauba or more likely Microcrystalline wax, Carnauba being a higher than hand temp melting point and microcrystalline being similar higher temp. and better at water and hand mark repelling.

Anything wanting Oil finish is done with Finishing Oil or Hard Wax Oil for extra robustness, both being polimerising and forming a hard sealed surface.

Most soft waxes are a blend of Bees wax, carnauba etc. and are fine for display on the shelf but will dull over time if handled a lot due to low hand temp melting point of bees wax.

 

[Dalboy]

I will go the same as CHJ stated. Sharpen the tools regular they only need a very light touch up to keep them sharp no need to grind half the tool away doing so.

The softer the wood the easier it is to get this problem, that is not to say that it will not happen with harder woods.

 

[Paul Hannaby]

The two areas of torn grain are where you are approaching the end grain and are generally 180° apart. The best way to deal with them is not to put them there in the first place.

You didn't mention what tool you are using to make the bowl. If it's a scraper, put it away and find a good bowl gouge which is very sharp, then sharpen it again just to make sure! ;-) By positioning the gouge to give more of a slicing / shearing cut, you should be able to minimise tear out.

 

[kirso]

Thanks for replies.
I didn't have a lot of option with grain as it was a bought blank.
I know I need to sharpen my tools better and more often. But I was eering on the safe side and tried not to mention that as had been warned its a bad discussion topic.
The information being given is very helpfull and appreciated. This is a new hobby and there's a lot to learn just on the basics.
Thanks

 

[CHJ]

I know I need to sharpen my tools better and more often. But I was eering on the safe side and tried not to mention that as had been warned its a bad discussion topic.

Sharpening in wood turning circles is not treated as such a black art as for some in the flat world.
There are individual preferences between bench grinders and belt grinders and personal preferences on grit types, and often influenced by personal finances, but in the main you just need a mechanically robust cutting edge that a good free cutting abrasive in the 120-240 grit range that's intended to handle HSS produces. In all but a few specialist cases that will be fine, any attempt to refine the edge like a carvers gouge is a waste of time in 99% of turning, fine wire edges will be gone in the first revolution. Remember the tool is traveling through the wood at something like 26 feet per second often in a very abrasive media, so regular quick light dressing of the cutting edge is the key, especially so for those last few final finish in cuts.

I do a lot of turning with pieces glued up with Cascamite. One hit on a join with excessive squeeze out will take the cutting edge off HSS in one revolution to the point it will not cut and I have to resort to using a carbide tool to remove it.

 

[minilathe22]

I have personally found that making sure your toolrest is very close to the work also helps create a cleaner cut. I was having trouble like this with some small bowls because I did not have a curved toolrest that fit well into the bowl shape.

 

[Phil Pascoe]

I didn't have a lot of option with grain as it was a bought blank.

Don't put it there in the first place - I think he meant don't put the tear there in the first place, not don't position the end grain where it is - no matter how you cut your blank or where in the tree it's from you are bound to get end grain somewhere.

 

[monkeybiter]

pm sent.