Thread: Bugger! Now I have gone and ruined it...

1. Use a card scraper, or

2. Use 80 grit on a light sand, don't push. Then clean the work-piece (wipe and vacuum is good).

Is there a vac attached to the sander?

Move to 100 grit and sand till the big scratches are gone, vacuum, repeat with 180, 240, 320, 400 etc

Note: I think your problem is you have not cleaned the work after sanding and a 'rock' has been picked up and ground into the surface.

Try also hand sanding between grits to remove the spirals

Torb,
Mate that's what 80 (and 40 ) grit do .. they scratch!! You might as well go out and rub your work on the concrete. In fact you might get a better finish if you did. Those grit sizes are for removing material quickly, not finishing!!

You need to get some 180 then 240 and so on to finer and finer grits until you get the desired finish.

Ian

Thanks guys. Will do.

The sander does have a vacuum bag attached.

Crikey mate,

whenever I make a cutting board, I just do the usual sanding thing then I get my cleaver and my steak knife and give the board a work out like you wouldn't believe till it looks as if it has had years of bodies and vegies of course, (must eat your vegies) over it! Best looking blocks around so don't stress over a few scratches mate, it's a part of the process.

Do it ! Oddjob1

Agree with the Post's above .

If you are going to get rid of the scratches, start at 100/120grit, then work you way to the finer grits , do not jump more than 1 grit.

Remember that after a few weeks use any scratches on the block will never be noticed.

Jeff
vk4

Thanks for the advice.

Now to a stupid question.

I understand that the 40 and 80 were course and rough which caused the problem. I have now completed a good pass using 120 and it looks a bit better.

If the 120 takes out some of the scratching, or reduces the depth of the scratch, why won't continuing using the 120 fix it completely?

(I have just ordered some 180, 240 and 320 but it will take a couple of days to get to me.)

Wipe the surface with metho, allow to dry. This helps raise the grain between sandings. You can use water but it is much slower drying. The metho evaporates almost instantly.

Torb,
Every grade of abrasive "scratches".
It's just that the scratches get progressively smaller the finer they get.

As Groggy pointed out, you may have picked up a foreign object when using the 80 grade. I would suggest that you keep using the next finer grade i.e. 120 until you remove them but, as I said, the 120 grade will produce it's own set of marks, which you will need to remove with 180 grade and so on until you are happy with the finish.


Ian

Now I really don't understand!

I followed the advice and destructions above, including the turps trick (which is beauty.)

No matter what I did, whilst I could reduce the scratches, they were still very evident. So, I decided to take my planer to it and see what happened.

The first attached picture is the end grain of the wood as it arrived. Its pristine.

The second picture is of my end grain cutting board. The two blocks on the right are sanded down to 240. The two middle blocks have been planed by .2m. The two left blocks have been planed by .6m. Notice, what appears to be scratch marksare the same all the way through, right down to the .6m depth that has been shaved off.

???????? I simply do not understand. Those 'scratch marks' going across the grain at .6m depth can't be caused by the sander.

The only thing I can think of is, does it have something to do with the clamping? if so, is that normal or is the wood defective? (The wood is Kwila and Manilkarra.)

That is checking through the drying process
It is in the wood.

TORB,

Checking goes very deep in to the timber, you will not get it out, you will have to either accept it or look for timber which is clear of checks.

I would just sand out the burn mark, and sand and finish the board. .

.Jeff

Thanks for that! So what is the good news?

I now understand and will keep this as a sacrificial experiential job and finish it off (partially) to make sure I have all the processes down pat. So, its a learning experience, but it was always designed to be that, and if the first one worked, it would have been a bonus.

So, now I have two questions. The first is it regarded as a defect in the timber?

Secondly, and more importantly, how do I get timber without the checking problem? (I live in the Southern Highland so a trip to Sydeny is not out of the question if necessary.)

My understanding is that checking is a normal process which occurs through drying. The core remains wet, where the outside of the timber begins to dry. This results in some stress in the fibres, which get pulled in all directions causing the cracks...im probably wrong

Not sure much can be done at this stage but sounds like the wood was still a bit wet. Maybe try to find out if the timber is fully dry/seasoned next time...maybe a sealing product could help?