Avoiding stains on blanks

Signed-In Members Don't See This Ad

Tiger

Member
Joined
Feb 15, 2009
Messages
245
Location
Melbourne, AUSTRALIA
Every now and then when I'm working on light coloured blanks such as oak or olive wood I notice that the grain seems dirty like it has been touched by someone with dirty fingerprints. This is particularly evident on blanks with cross grain rather than straight grained features. I then battle to remove the stain, sometimes having to go back to 120 grit and even then not being completely successful and removing the stain. I was working on some olivewood, sanded down to 600 it was all going fine and then I rubbed a bit of acetone on it to clear any residual dust, the grain became dirty in places and actually looked torn, to the eye it seemed that as though someone had gone over it with 80 grit sandpaper. I think I'm fairly careful when it comes to handling the blanks but maybe I need extra precautions on these sort of timbers, what do you think?
 
Signed-In Members Don't See This Ad
Joined
May 1, 2012
Messages
217
Location
Destin, FL
If you are getting this towards the middle of the blank, it can be sanding dust or the sandpaper particles getting trapped in the grain. If it's at your bushings, then it is probably sanding residue from the bushings. The cross contamination can be really bad with light woods and contrasting woods laminated together.

Best way I have found to reduce it is to spray the blank with a light coat of sanding sealer or CA. You can also try compressed air to get it out of the grain if you don't use my suggestions but the results are pretty random as to how effective it will be.
 

Tiger

Member
Joined
Feb 15, 2009
Messages
245
Location
Melbourne, AUSTRALIA
If you are getting this towards the middle of the blank, it can be sanding dust or the sandpaper particles getting trapped in the grain.

The cross contamination can be really bad with light woods and contrasting woods laminated together.

Best way I have found to reduce it is to spray the blank with a light coat of sanding sealer or CA.

Thanks DT, it is towards the middle rather than the end but sometimes the end gets it as well.

I forgot to mention that it's at its worst with light and dark woods laminated together, I haven't had a satisfactory result yet with those types of pens unless the blanks are all straight grained.

So you do your sanding and then spray the blank with CA/Sanding sealer? I did that and then used Acetone and got a poor result.
 

KBs Pensnmore

Member
Joined
Oct 16, 2010
Messages
834
Location
Murray Bridge 5253 Australia
If you are getting this towards the middle of the blank, it can be sanding dust or the sandpaper particles getting trapped in the grain.

The cross contamination can be really bad with light woods and contrasting woods laminated together.

Best way I have found to reduce it is to spray the blank with a light coat of sanding sealer or CA.

Thanks DT, it is towards the middle rather than the end but sometimes the end gets it as well.

I forgot to mention that it's at its worst with light and dark woods laminated together, I haven't had a satisfactory result yet with those types of pens unless the blanks are all straight grained.

So you do your sanding and then spray the blank with CA/Sanding sealer? I did that and then used Acetone and got a poor result.


Try coating with sanding sealer or CA BEFORE sanding.
 

nava1uni

Member
Joined
Mar 30, 2008
Messages
4,936
Location
San Francisco, CA, USA.
It sounds like you are getting a mix of the sawdust from the darker wood laying on top of the lighter wood. It would be best if you blew the dust off before you do anything else. Putting sealer or CA only lock the dust into the the grain and you get that muddled appearance. If you put on a thin layer of CA before you sand then you can remove it with air much easier and less residue.
 
Joined
May 1, 2012
Messages
217
Location
Destin, FL
It sounds like you are getting a mix of the sawdust from the darker wood laying on top of the lighter wood. It would be best if you blew the dust off before you do anything else. Putting sealer or CA only lock the dust into the the grain and you get that muddled appearance. If you put on a thin layer of CA before you sand then you can remove it with air much easier and less residue.

This is exactly correct. Sorry I wasn't more specific. Blow out the dust after as fine a shear cut as you can get. Spray with sanding sealer or coat with one coat thin CA. Then start your sanding. If you start to see the dust again, blow out and recoat with CA.
 

Tiger

Member
Joined
Feb 15, 2009
Messages
245
Location
Melbourne, AUSTRALIA
I turned another pen tonight and experienced a similar result. This time I observed everything more carefully. I found that the contamination occurred straight after I sharpened the skew chisel. I wanted to make a final cut before sanding and I went to the diamond stone and then to the buffing wheel with the Veritas green rouge. I then made a nice fine cut but the blank was then stained with the green rouge but possibly some fine steel filings. I sanded back to 120 grit but was still not totally successful in removing the staining :mad:. Any ideas on how I could have got rid of the staining, would the air compressor have got rid of it? I must say that it was well and truly embedded in the grain of the pale olive wood blank.
 

Russianwolf

Member
Joined
Jul 13, 2007
Messages
5,690
Location
Martinsburg, WV, USA.
one other thing I'll mention.

a fresh piece of LIGHT colored sandpaper.

Don't use the black automotive sandpaper when sanding the light woods, try the yellow sandpapers. Yeah they tend not to last as long, but the grit from the paper can cause contamination as well as dust from what you are working on.
 

KenV

Member
Joined
Oct 28, 2005
Messages
4,720
Location
Juneau, Alaska.
Two points --

1. The green polishing compound from Lee Valley contains coarser aluminum oxide abrasive in with the waxes and chromium oxide. It may be less effective for sharpening than the diamond hone.

2. Your description suggests that your wheel over loaded with green polishing compound. The light load should not be leaving significant compound behind. In any case, the compound will clean off with a wipe with a mineral spirits dampened cloth or paper towel.


Once you get a wax based contaminant into the wood grain, mineral spirits may wash it out or may not.

Clean tools, clean cuts and light sanding.

(Holly is the worst of woods to keep white, and bloodwood & Paduk are the worst for cross staining).
 

Tiger

Member
Joined
Feb 15, 2009
Messages
245
Location
Melbourne, AUSTRALIA
Thank you all for your contributions, I have never cleaned tools after sharpening or honing but I'll give that a try. Will also give the mineral spirits a try, I'll try another pen tonight and report back.
 

Tiger

Member
Joined
Feb 15, 2009
Messages
245
Location
Melbourne, AUSTRALIA
I tried some more olive wood tonight and although the dark specks are less than before they're still there. They appear before I sand so they must be caused by the tool which I cleaned before I applied to the work. Furthermore I cannot remove the specks and they seem particularly ingrained, mineral spirits does nothing to remove them.
 

Tiger

Member
Joined
Feb 15, 2009
Messages
245
Location
Melbourne, AUSTRALIA
Photos

Attached are photos. The photo is as clear as I could get it and it shows the right side of the barrel that has some streaks at right angles to the darker grain. I have not been able to get rid of the streaks and I've tried mineral spirits and sanding.
 

Attachments

  • Stained barrel 5.jpg
    Stained barrel 5.jpg
    10 KB · Views: 89
  • Picture 010.jpg
    Picture 010.jpg
    26.5 KB · Views: 98

KenV

Member
Joined
Oct 28, 2005
Messages
4,720
Location
Juneau, Alaska.
Photos are too dark for me to be able to use -- and I get pixelation when I zoom in in Photoshop. Someone else may be able to see more.

Odds of filing being caused by either a high speed steel or carbide tools shedding particles is small -- especially if you wiped the tool off. Hard tough tool edges do not shed many particles of metal/carbide.

So where else in your system can the contamination be coming from??

Dark sand paper??


You are using bushings??

Soft steel from bushings can migrate if you are getting a bit close and turning steel swarf.
 

Tiger

Member
Joined
Feb 15, 2009
Messages
245
Location
Melbourne, AUSTRALIA
I apologise for the photos, they are a bit clearer on the phone but when I try to upload they are significantly compressed and that makes seeing the detail more difficult. It can't be the sandpaper as I didn't sand the barrels and the marks are still there. I do use steel bushings but I'm fairly careful when I use my tools not to hit the bushings. Still suspect the tool and maybe it isn't as clean as I think but I now clean them with mineral spirits and this staining only seems to occur when I use the skew and I try and rub the bevel to get a nice finishing cut.
 

Tiger

Member
Joined
Feb 15, 2009
Messages
245
Location
Melbourne, AUSTRALIA
I can now only assume that there was a small amount of honing compound/dirt on the tool and that is what the stains are, it has to be as it occurred before I started sanding. I kept going with the skew but could not get rid of the stains. It seems that the dirt got into the pores of the wood and went very deep into the blank, nothing removed it, not the air compressor, not mineral spirits, nothing. Not sure what to do if this occurred again, can you use sanding sealer before making the final skimming cuts preceding sanding?
 
Top Bottom