Lines in CA finish

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Woodchipper

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I'm taking a break for two reasons- to let the knees quit screaming and to ask a question.
I'm applying Tite Bond Thin CA to a cherry blank. I'm using a paper towel to apply the CA then give it a quick shot of accelerator. I'm noticing that the CA has lines in it like sanding marks. I checked after sanding under a bright light and a magnifying glass to check for sanding marks before applying CA. None there. Before I did something I would regret, I thought I would put the question to the forum. I have MM and Hut Ultra Gloss. What is recommended? Your help is most appreciated.
Using a high RPM but noticed that another thread had one person going down to 500 RPM.
 
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aj r

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I was having the same problem. Tracked it down to the Meguires plastix polish I was using at the end. Switched that out to a non abrasive polish (Nu Finish car polish) and everything has been fine since.

Might be worth checking it out with the magnifying glass after your micromesh, but before the polish.
 

elyk864

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I apply my CA with flexible foam. You can buy it at a hobby store in sheets for a dollar usually. I cut it into little 1.5in x .75in pieces. I also apply my CA turning my lathe by hand. To me it seems it prevents the CA from getting bubbles from the force of spinning. I then sand smooth with 400, 600, 1500, then onto plastic polish. It ends up looking like glass when done.

EDIT: http://www.michaels.com/12x18-foam-sheet-by-creatology/M10597609.html?dwvar_M10597609_color=Medium Pink (I just get the white)
 

duncsuss

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I checked after sanding under a bright light and a magnifying glass to check for sanding marks before applying CA. None there.
Try giving the blank a wipe with a small amount of DNA (or mineral spirits) on a paper towel and look again while it's still wet. You might see some lines that didn't show when it was dry -- and the paper towel might pick up some fine dust that was masking the scratches.

You don't say if you stop the lathe and sand up & down the blank with each grit before going to the next higher grit -- it might be worth adding this step if you don't already do it. (Sanding "with the grain" to eliminate circumferential sanding scratches.)
 

magpens

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You do have to sand the CA after you apply several coats.

Sand LENGTHWISE with the lathe switched OFF, turning the lathe headstock by hand.

I start with 240 grit and gradually work up to 1500 grit.

If the CA is quite thick, you might have to start with 180 grit.

Using your discretion and experience, you have to sand the CA until there are no shiny patches
using the 240 grit. After that, the sanding goes pretty quickly as you work your way up to 1500 grit, always trying to get rid of all shiny spots.

After the sanding, use a two- or three-stage friction polish.
I use Mequiar's automotive heavy scratch remover first, followed by Novus 3 and then Novus 2 (and sometimes follow that with Plastix polish, which adds a little bit of extra lustre).
 
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Woodchipper

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I sand from 150 to 400 while turning. I then shut off the lathe and sand parallel to the grain to get any scratch marks out. The blank I had today looked good. I put about 8 coats of CA on the blank with accelerator on each coat. I tried to sand one blank and wound up with a mess. I don't want to ruin this blank as the grain is really nice.
We had two guys in our turning club demo pen making and I don't recall either one sanding the CA. Will look at the blank and go from there. Thanks. Might put the blank aside and experiment with another piece of wood tomorrow. Little League World Series games start tonight so many things are on hold for a while.
I apply my CA with flexible foam.
Have lots of it.
 
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My 3 cents, Adam, I think got it dead on.
I also turned several acrylic pens and sanded up thru the grits; perfect finish under the mag glass. Then I put a plastx coat on and lo and behold, under the glass were lots of scratches that were not there before. I sanded the pen back and took it to the buff and polish wheels, perfect finish !!
Hope this helps
Irv
 

Mortalis

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I have found that if you apply accellerator before there are 3 to 4 self dried coats of CA that white lines and/or bubbles can be more likely to appear. Watch the wood n whimsies video and he explains it also. I dont Plasti-X CA. I will use Plasti-x on acrylic polanks without using any CA. Just how I roll anymore.
 

Talltim

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Well every one does it a little differently. We sand through 600 and go through the nine rounds of mm on the wood. Then apply the CA and go through the process again through the mm. Then buff with white diamond.

We do the parallel during the wood stage as well.

We only apply accelerator when using medium ca. and sometimes then prefer to apply patience instead.
 
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Woodchipper

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Went to the shop and took a good look at the blank. After much consideration, I decided to try the wet MM and turn at a low speed. Good idea to put an old towel on the lathe! Anyway, I went through all the MM strips, dried the blank and looked at it with a magnifying glass. The lines were, as some were correct in their diagnosis, in the wood! Evidently, I didn't sand with the grain enough. They are not real evident unless you really look close.
Will sand with the lathe turning and let the wood stand proud of the bushings and then sand down with the grain to the bushing size. I understand that there are those who turn with a skew and have little or no sanding. Got that on my list of things to learn.
Thanks to all for their replies as there is a lot of information that I can use in the future. Now....back to the shop to work on another blank.
 
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Hit the wood with some denatured alcohol or something prior to applying finish to really see any lines, etc that might be there. Obviously darker woods are going to show them more. 320 grit is usually plenty for hiding the sanding lines but if you ONLY sanded with the lathe running there are usually some circles that show up later and remind you to sand with the grain. A light touch is going to be better than a heavy hand. Pushing hard means scratching, not sanding. I've had my share of pens I had to turn/sand the finish off of and start over because of lines in the substrate. This last one I did with aluminum segments was a bear...
 

Mortalis

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Well every one does it a little differently. We sand through 600 and go through the nine rounds of mm on the wood. Then apply the CA and go through the process again through the mm. Then buff with white diamond.

We do the parallel during the wood stage as well.

We only apply accelerator when using medium ca. and sometimes then prefer to apply patience instead.
I dont like to use Accelerator at all but some times I'm in a rush. I will apply 5 - 6 coats thin and let it self dry. Then 5 - 6 coats medium, usually allowing it to self dry then I go through all the spongy squares of the MM and check the finish under a Bausch and Lomb StereoMicroscope I purchased on ebay (old job habits dont die) to see how bad the scratches are. If need be I will refinish with the MM from about half way through the deck up.
 

leehljp

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Just for clarification information - I personally do not sand lengthwise. Rarely have. I don't have rings. ON the other hand, I have been working with wood since the '50's as a pre-teen. I learned how to sand out sanding marks even going cross grain. But that is from experience.

Without considerable experience, sanding with the grain is the utterly best way, but it is not an absolute to get sanding rings out. On many occasions, I use the sharp scraper chisel to produce SP 600+ like finishes without sanding rings. A large part of getting sanding rings out is using 400, 600, 800 equivalent SP and the use of "touch" and "feel" along with good eyesight and patience.
 
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Woodchipper

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Hank, could you show a photo of your scraper? I have one that is about one inch wide and has a radius on the cutting edge. Same thing? I seen several configurations of scrapers.
 
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