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-   -   Met my match? (http://www.penturners.org/forum/f28/met-my-match-156013/)

Tiger 08-09-2018 10:25 PM

Met my match?
 
Iíve been working on some type of burl, not exactly sure what type but have made a couple of other pens with it that had no problems but on this one which is a slimline Iíve had all sorts of dramas, namely fogging in the CA finish. So I turned the pen and applied the CA finish, looked ok MMd and on the final step, it started fogging. So I stripped it back to bare wood applied DNA 3 times, applied the CA and the fogging appeared in the same spots, this time in other areas as well. Stripped it again, this time I tried drying with Acetone, reapplied CA, same result with the fogging. Stripped again, dried with Accelerator, rereapplied CA, same result. I donít often give up, but this time I just went for EEE and Shellawax finish, the finish lasted just a few handlings and now looks pretty ordinary. My first instinct says that thereís moisture in the timber but Iíve had it for a while and used it on other pens eg JR gent with no problems. Ca is fresh somrule that out, tried applying it at night and middle of day so well rule that out, humidity not a consideration either so what does that leave, as I canít stand the pen the way it is now. There are spots that the CA just doesnít want to adhere to, although it was adhering better on my first attempt using the CA.

1080Wayne 08-10-2018 12:05 AM

Moving to NSW might help . I guess a last desperate attempt would be to put it in the oven at 170F overnight . Won`t help the wood/glue bond , but might the finish problem .

Tiger 08-10-2018 02:09 AM

NSW is only several hundred miles away, but if no one else comes up with a better solution, I might just do that. Today is actually the warmest day for sometime, 19 C.

jttheclockman 08-10-2018 02:56 AM

Quote:

Originally Posted by Tiger (Post 1989777)
Iíve been working on some type of burl, not exactly sure what type but have made a couple of other pens with it that had no problems but on this one which is a slimline Iíve had all sorts of dramas, namely fogging in the CA finish. So I turned the pen and applied the CA finish, looked ok MMd and on the final step, it started fogging. So I stripped it back to bare wood applied DNA 3 times, applied the CA and the fogging appeared in the same spots, this time in other areas as well. Stripped it again, this time I tried drying with Acetone, reapplied CA, same result with the fogging. Stripped again, dried with Accelerator, rereapplied CA, same result. I donít often give up, but this time I just went for EEE and Shellawax finish, the finish lasted just a few handlings and now looks pretty ordinary. My first instinct says that thereís moisture in the timber but Iíve had it for a while and used it on other pens eg JR gent with no problems. Ca is fresh somrule that out, tried applying it at night and middle of day so well rule that out, humidity not a consideration either so what does that leave, as I canít stand the pen the way it is now. There are spots that the CA just doesnít want to adhere to, although it was adhering better on my first attempt using the CA.

Not sure I followed all you did but, if you striped the wax off and tried CA again it is possible that the wax is now in the pores of the wood and thus not allowing the CA to adhere to those spots and being a slimline the wood is very thin so sanding down past this is probably out of the question. Would suggest a solid finish such as polyurethane. Or go back to wax.

As far as cloudy that is probably moisture. You did not say if you wet sand your MM and I bet you do and that is where you are picking up moisture. Again the amount of coats can have an effect on water penetration as well as if the ends of the blank are not sealed they will wick up moisture and get under the CA. This is my best educated guess. Always seal the ends of a wood blank before MM especially wet sanding.

MDWine 08-10-2018 06:32 AM

One of the many reasons I dislike a CA finish.
I use lacquer, coat after coat over time. The drawback is that it takes a while, not the immediate gratification (?) of CA.
I hope you find your culprit and get past it, I know it is frustrating!

leehljp 08-10-2018 11:34 AM

When you MM it, are you doing this while it is turning on the lathe? If so, and you did use DNA, moisture in the wood can and will come out.

4 things I see in this that could possible affect the cloudy outcome.

1. you are in Australia in August, winter, highs close to 70į (20įC), lows upper 40į's (10į- 12įC) Cloudiness occurs more in humidity climates than dry. I see that your humidity is swinging from around 50%. Not bad. But Cooler weather - 70-75F/23-20C and below affects cloudiness more than when 80F/25-26C and above.

2. When MM'ing on the lathe with it turning, it heats up the CA. The heat on the CA from the friction of turning will draw any moisture in the wood to it, and you will have cloudiness. The cooler the temp, OR the higher the humidity the more susceptible clouding becomes.

This is all a moving target with humidity swings and temperature swings and it can change from day to day.

3. IS the burl wood oily wood by any chance? Oily sap may be vaporizing.

4. DNA cleans oil but often adds moisture into the wood. Not all of DNA will always evaporate, some penetrates and stays in the wood. After using DNA on a wood blank, I will use a paper towel on it while it is turning to heat it up. This "heating" dissipate the DNA moisture that soaked into the wood.

Tiger 08-11-2018 12:12 AM

Update
 
Iíve had another go at this, I tried a sanding sealer, same result as before. I found a small piece of the same burl, turned it, sanded it and then started to apply a few coats of thin CA. Result? The thin CA would not bond to the blank in some spots. A few coats of thin later, still not bonding at the same spots. I then used some medium CA and after a few applications it bonded. I donít know whether the thin CA just didnít bond or it spilled over to other areas or as Hank mentioned some sort of vaporising occurred. I went back to the original slimline blanks and though it took a number of applications I managed to lay a CA finish. When I started sanding, I noticed that where there seemed to be no bonding, the finish looked rough/dirty but I sanded lightly and not taking any chances I didnít MM wet and got through it.
MD, I was close to giving up on CA, but 90% of the time it works ok and is reasonably predictable.
JT, I find TBC generally seals the ends so even with wet MM I havenít experienced too many issues.
Hank, your 3rd explanation could provide a clue, I didnít think the burl was oily and Iím not sure how Iíd check but there was some sort of vaporising or non adherence to the same spots on the blanks.
I hope this helps someone, canít really explain this but Iíve used a ton of CA, all in the pursuit of knowledge.

Wildman 08-11-2018 09:04 AM

One thing to remember about burl wood has crazy grain or cell structure of the wood itself. Technally chemical make up of burl wood can and does differ from normal wood. I would try a different film finish like lacquer or poly.

If use lacaquer would allow each coat to dry thourghly between coats. What makes me mention lacquer only because each recoating mells into previouse coat.

If use poly might select a water based or borne product. Clear water based finishes normally don't impart an amber hue. Poly does take longer to dry and may or may not require very light sanding between coats.

1080Wayne 08-11-2018 01:40 PM

Quote:

Originally Posted by Tiger (Post 1989889)
Iíve had another go at this, I tried a sanding sealer, same result as before. I found a small piece of the same burl, turned it, sanded it and then started to apply a few coats of thin CA. Result? The thin CA would not bond to the blank in some spots. A few coats of thin later, still not bonding at the same spots. I then used some medium CA and after a few applications it bonded. I donít know whether the thin CA just didnít bond or it spilled over to other areas or as Hank mentioned some sort of vaporising occurred. I went back to the original slimline blanks and though it took a number of applications I managed to lay a CA finish. When I started sanding, I noticed that where there seemed to be no bonding, the finish looked rough/dirty but I sanded lightly and not taking any chances I didnít MM wet and got through it.
MD, I was close to giving up on CA, but 90% of the time it works ok and is reasonably predictable.
JT, I find TBC generally seals the ends so even with wet MM I havenít experienced too many issues.
Hank, your 3rd explanation could provide a clue, I didnít think the burl was oily and Iím not sure how Iíd check but there was some sort of vaporising or non adherence to the same spots on the blanks.
I hope this helps someone, canít really explain this but Iíve used a ton of CA, all in the pursuit of knowledge.


The rough/dirty appearing areas can be ones where the CA has really wicked into the end grain . Areas like that will absorb a lot of CA before appearing to have a CA finish .

Tiger 08-12-2018 01:54 AM

Quote:

Originally Posted by 1080Wayne (Post 1989923)
Quote:

Originally Posted by Tiger (Post 1989889)
Iíve had another go at this, I tried a sanding sealer, same result as before. I found a small piece of the same burl, turned it, sanded it and then started to apply a few coats of thin CA. Result? The thin CA would not bond to the blank in some spots. A few coats of thin later, still not bonding at the same spots. I then used some medium CA and after a few applications it bonded. I donít know whether the thin CA just didnít bond or it spilled over to other areas or as Hank mentioned some sort of vaporising occurred. I went back to the original slimline blanks and though it took a number of applications I managed to lay a CA finish. When I started sanding, I noticed that where there seemed to be no bonding, the finish looked rough/dirty but I sanded lightly and not taking any chances I didnít MM wet and got through it.
MD, I was close to giving up on CA, but 90% of the time it works ok and is reasonably predictable.
JT, I find TBC generally seals the ends so even with wet MM I havenít experienced too many issues.
Hank, your 3rd explanation could provide a clue, I didnít think the burl was oily and Iím not sure how Iíd check but there was some sort of vaporising or non adherence to the same spots on the blanks.
I hope this helps someone, canít really explain this but Iíve used a ton of CA, all in the pursuit of knowledge.


The rough/dirty appearing areas can be ones where the CA has really wicked into the end grain . Areas like that will absorb a lot of CA before appearing to have a CA finish .

Yep, probably the correct assessment, guess thereís nothing you can do to prepare that end grain for the CA finish.


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