# Dirty Little Spots



## twhite (Feb 22, 2006)

I am having an issue with what looks like sanding dust caking up in the grain of some of my turnings.  It seems to be more problematic with lighter woods such as ash, oak, maple and hickory.   Maybe I am just not seeing the build up in the darker woods as easily as I do in the lighter ones.   

I have been experimenting with several finishing techniques; most recently I have been trying Fangarâ€™s CA method.  Results have been good but the woods have all been darker.   This past weekend I turned a piece of curly hickory and the build up is quite noticeable.   When sanding I start with 150 grit and sand while the lathe is running, then cross sand with the same grit with the lathe off to clean up the deeper, circular scratches.  When I am ready for the next step I always wipe the blank with a dry blue shop towel before turning the lathe back on and continue with the next grit.   The hickory started showing build up very soon in the sanding process, before the 320 grit.  I tried going back down to 150 to clean up the build up but it just wonâ€™t go away.  In fact it seems to just continue to build up.

I have made several changes to try and prevent this build up.  One was to change from a dark paper back sand paper to a lighter, cloth backed sand paper.  That helped a little but not enough to stop the build up.   I have also tried wiping down with DNA after every step.  No change with that either.   

Could the blue shop towels be the problem?  These are the paper kind you get can get a Walmart or in bulk from Samâ€™s.  Do they tend to â€œshedâ€ blue lint or dust particles?  Are my bushings dirty and need to be cleaned?  Perhaps it is a chemical reaction to the metal bushings and the acidity in the wood I am using?  Or is it just in the wood itself and some woods are more prone to this than others?

Comments anyone?


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## JimGo (Feb 22, 2006)

Toni,
Welcome to IAP!  Since this is your first post, I'll pass on the same admonition that was given to me... POST LOTS OF PICTURES!  We love pictures! []

Have you tried using several coats of CA or another substance (like Myland's Cellulose Sanding Sealer) as a sealer BEFORE you start sanding?  If you use enough CA to fill the open spots and get a good coat over the entire blank, then sand it down as normal, you should get a nice finish without too much dust stuck in the open grain.


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## vick (Feb 22, 2006)

I used to get black build up in the wood pores from sanding the bushings.  Also try putting Denatured Alcohol (DNA) on the shop towel or hit it with compressed air or shop vac the dust out before going to the next grit.


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## gerryr (Feb 22, 2006)

I used to have the same problem, but I discovered that it was caused by being a sandpaper idiot.  I didn't know not to use dark colored sandpaper.  I also didn't know that sandpaper quality varies.  Now I won't use anything except Norton 3X or Klingspor Gold.  Neither of those is cheap, but they're worth it.


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## Fangar (Feb 22, 2006)

Like vick said DNA is good.  150 seems a littl agressive to me to being with if you take a nice clean cut with a scraper or skew first.  I start at 240, and sometimes 340.  If you have an abormally graining wood (Wenge), maybe try to saturate you blank with the thin CA prior to sanind.  It might help to seal some of those pores first.  Then have it it with some 240 grit.  Try that out.

Fangar


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## Dario (Feb 22, 2006)

WELCOME!!!

You got a lot of good advise already but I'll reinforce them.

Clean before applying finish with DNA or compressed air.
Use better sandpaper...I use Klingspor Stearate sandpaper.  Avoid the black one on light colored wood.

Sealing with CA before sanding will work but you will use up more sandpaper that way and sanding may take a bit longer too []

Good luck!!!


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## twhite (Feb 22, 2006)

Thanks for all the information.   I will definitely give these a try and see if they solve my problem.  I had not thought of a CA layer or sanding sealer BEFORE starting to sand, makes sense.  I also really had no idea that one sand paper would be so much different than another.   More money â€¦.

Thanks again!


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## RogerGarrett (Feb 27, 2006)

> _Originally posted by Dario_
> <br />WELCOME!!!
> 
> You got a lot of good advise already but I'll reinforce them.
> ...



Here is a question from a relative novice to the finishing step.....

When you apply CA (thin or thick), how do you apply the first coat?  I've read through Fangar's advice - but some of the steps confused me - due to lack of experience - I need someone to fill in the gaps here. 

Do you then sand after it dries.....or does the use of sandpaper heat  the CA up and it sets up from that process? 

You guys sure know a lot.

Best,
Roger Garrett


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## RussFairfield (Feb 27, 2006)

Lathe speed?  Sanding problems can be the result of heat from sanding too fast.

If you are sanding at the same speed as turning, slow down.

If you are melting the adhesive on the sandpaper, slow down.  

Try 500 RPM


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## Dario (Feb 27, 2006)

Roger,

I apply CA at the slowest speed.  I've tried different applicators (except with BLO) and all seemed to be almost identical to me.  By applicator I meant the backing I use to spread the CA.  

I used batting material which is very nice but can get nasty when it gets caught.
Tried using the back of sandpaper and it works well.
Also tried waxpaper but seems like the besta nd most economical and readily available is the plastic wrappers that the kit comes in with.

Again at the slowest lathe speed, I position the plastic near the bottom.  If you are facing the headstock the plastic is perpendicular/tangent to 7 o'clock of the tube.  Drizzle some CAat around 2-3 o'clock and let the plastic help you spread the CA as evenly as you can.  You may have to do this in sevaral passes to attain the thickness you want/need.  You can also do thsi with the motor off.  Let teh CA cure by itself...no accelerator.

After CA cured well.  Start sanding.  I usually start at 400 depending on how nice the CA spread.  As Russ said...sand at slow speed and keep on cleaning your sandpaper (slap it a few times at the tool rest).  If there is gunk, either remove it or move on to a cleaner part of the sandpaper.   I usually start off my sanding parallel to the tube.  Especially when I apply CA with running motor.

DO NOT SKIP sandpaper grit.  If you do, it will just cause you more time to do it right or you may never get it right.

If all else fails...check Russ' site.  The link is under his signature []

Good luck!


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## alamocdc (Feb 27, 2006)

Concur with James (Fangar). DNA and I won't start at anything more agressive than 220 (usually 320).


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## RogerGarrett (Feb 27, 2006)

> _Originally posted by Dario_
> <br />Let teh CA cure by itself...no accelerator.......[SNIP
> 
> After CA cured well.  Start sanding.  I usually start at 400 depending on how nice the CA spread.......................[SNIP]
> ...



Thanks to all who responded.  Just a few more questions:

1.  Is there a particular, fast set-up CA you recommend?  I have only kept the thick stuff in my shop until I began to read about thin - and I will go purchase......just want to get the stuff that works best.

2.  How long does it take for this stuff to set up?  I would think a long time.........

Best,
Roger Garrett


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## Dario (Feb 27, 2006)

Roger,

Not sure if it is the high humidity here in San Antonio, but CA seems to cure fast...even thick.

Can't argue with Fangar's finish and I am probably one of those who bugged him about it [] so try to get as much as you can from his tutorial.

FYI, I try to SEAL my wood with thin CA before final sanding up to 12000MM.  Then apply the CA finish.  A bit too much work but I can't do it any other way if I really want/need a good CA finish.


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## RogerGarrett (Feb 27, 2006)

> _Originally posted by Dario_
> <br />FYI, I try to SEAL my wood with thin CA before final sanding up to 12000MM.  Then apply the CA finish.  A bit too much work but I can't do it any other way if I really want/need a good CA finish.



I've been reading about MM - what is it?  What do the numbers mean.

I'm so remedial in some ways - but not in others..............

Roger Garrett


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## Dario (Feb 27, 2006)

MM = micromesh the number is the grit.  It is a different sytem though and not similar to the usual American or European sandpaper grit grading system.

There are various sellers but I think Tangboy5000 (Charles) who is a member here sells them very reasonably.

MM may look expensive at first but it lasts like forever.  I am still using the first strip that I've been using for more than a year now. It is not bullet-proof...abuse it, and it will go bad in a minute.


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