question on thick CA

[Cloven]

The pens I've done so far, I've used a thin CA I get from a local hobby store. It's the consistency of water, it goes on really easily, but I only have maybe 2 seconds before it's set. I use a thick CA for gluing in my tubes because it gives me maybe 10 seconds to get the tube in before it starts to grab. The 50 cal pen I recently posted, I finished that with the thick CA because it was so porous, I wanted something that would fill it and maybe make something a little more even. I did my normal routine of 8 layers with a blast of accelerant between, then MM wet sand. The finish cured just fine, no clouding, no cracking, nice and glossy, but when I look at the shine line, I can tell that the surface is uneven. When I would finish with the thin CA, the shine line is perfectly even and you can feel it's a uniform surface.
My question is, when one finishes with thick CA, should you wet sand with 400-1000 grit sandpaper before then moving onto MM? Because it's so thick, it doesn't naturally flow out like the thin does. If I wet sand with black 400, I could see that would smooth it out, but would it scratch it up too much to polish out in the higher grits?

 

[wyone]

well I have never tried using thick for finish.. I typically use thin for the first 4-6 coats, then switch to medium

 

[1080Wayne]

I would suggest you dry sand with 400 or coarser if necessary to start with , until there are no areas which look shiny . At that point you should have a uniform surface which you can wet sand to a higher gloss .

I`m not sure that use of accelerant guarantees total fast cure of a thick finish . You may see some orange peel develop after a week or two .

 

[GaryT45]

After you put on the thick, put on a few coats of the thin to even out the surface.

My routine is one coat of thin, 6 to 8 coats of medium, then a final coat of thin, then sanding and polishing.

 

[plano_harry]

I used to use medium and thick, but I did the math and figured it was quicker to lay on 20 coats of thin than it was to put on a few thick coats and then fiddle with trying to level the ridges. I got much better results and less time spent sanding.

The hobby shop is fine if you run out but you will save a lot of money if you buy a 16 ounce bottle of EZ bond 50 cps from Exotic.

Don't worry about polishing out the scratches. If you are doing the lathe off longitudinal sanding, after 400 grit you should be able to go to the first MM pad with no problem. If you don't have a smooth matt surface from the 400 with no stray scratches, you need to get better paper. I use Abranet exclusively.

 

[navycop]

Not to highjack. Just need clarifcation.. You guys are using 400 wet/dry in the dry mode? I have been using it wet.

 

[plantman]

I find that there are several advantages to using thick CA as a finishing coat on my pens. First, as you pointed out, it gives you more time to work. Same for glueing tubes in. Second it builds up a surface quicker. Lesser number of coats, the better chance of not messing up the finish. Third, by putting on 8 coats of thick CA you are less likely to sand through to your surface. Fourth, it's just plain faster. If you are applying your CA correctly, you should have no ridges to begin with. Are you using a clean lint free white toweling to smooth out your CA as the lathe turns at it's lowest speed ?? Are you moving the toweling rapidly back and forth to smooth out the coats of Glue ?? You don't need to use accelerant between each coat, only the 4th and last. Your finish is only as good as the base you are applying it over !! This is where you should be spending your time gatting a smooth surface first. However, CA will fill any dips or voids in your surface. After the last coat of CA, your surface should require little sanding. I go right to 600, 900, or 1200 high grade cabinet paper. And yes the quality of the paper does make a hugh difference in your final finish. Sand end to end with the lathe off, removing any shiney spots that can be detected by having a light mounted over your lathe. Several points about sanding. Water never touches my lathes !! It's messy, just adds another contaminate to your finishing process, seeps into your end grain, and rusts your lathe. In all my many years of woodworking, I have never found a reason to sand a wooden surface beyond 400-600 grit. After that number you are either burnishing or polishing the surface, which is fine for acrylics. I have used my MM pads to 12000 just to see if it realy makes a difference. I haven't noticed any. Nothing can beat your fingertips or eyes for detecting an uneven surface !! I may be out of date and old school, but this is the way that the old masters taught me before the "micro age". Practice will make your finish perfect. Jim S

 

[plano_harry]

Wet 400. I only use dry on raw wood.

I also feel that using a MM pad as a backer on wet abranet gives me better results in flattening any high spots. Essentially a very soft sanding block. My first step is to sand lightly and then view the shiny/dull spots to see if more is needed, and where, and then continue until the low spots are dull.

Not to highjack. Just need clarifcation.. You guys are using 400 wet/dry in the dry mode? I have been using it wet.

 

[steve worcester]

Not to highjack. Just need clarifcation.. You guys are using 400 wet/dry in the dry mode? I have been using it wet.

Wet has the advantages of no dust and the finish in the slurry of water doesn't ball up and become another abrasive or stick to the paper as much.

 

[StuartCovey]

Try using a skew after you apply the CA.
I always bring my CA to a little bigger than the size I need and then use a skew to bring it back down to the correct size. This way I never have any ridges and it becomes a perfectly smooth finish.

Also it allows me to start buffing at a a higher grit.

Good luck!