Water running under end of casting

[danowenby]

Hello, all!
While polishing acrylic blanks that I am beginning to make, the water used on the polishing material wicks under the end of the blank. My mold is PVC pipe, which requires a light tap with a mallet to remove the blank. I turn with a skew chisel, dry sand up to 600g, then micromesh the full range wet. Do you have any advice on how to keep water from wicking between the brass tube and and acrylic and ruining the blank? Thanks heaps!!

 

[longbeard]

What glue are you using to glue the tubes in? I use 5 min epoxy, dont have the problem you are having, but I use a q-tip with thin ca on it. With a light touch, i run the q-tip around the ends. Do my wet sanding. After i do this, i sand the ends flush again, if not, you may not have a flush fit between the blank and the components or could cause a crack in the finish. This is how i do my ca finish on wood blanks. Should work fine on acrylic.


Harry

 

[edstreet]

Simple, keep water away from the blank.

 

[gbpens]

Seal the ends with thin CA as Longbeard suggests.

 

[seamus7227]

I could be wrong, but I'd be willing to bet you didn't paint the inside of your tube, or if you did, then not very well. What looks like water may very well be air pockets from the glue used that gives the appearance of water. Can you take some pictures to help us out?

 

[danowenby]

I am casting clear acrylic over a the brass tube after foil has been attached. Didn't think about sealing the end with CA. Will give that a shot, and a thousand gratitude of all kinds!!

 

[MillerTurnings]

I seal the ends with CA, figure a dab of insurance beats a ruined blank.

 

[mightymavkev]

+1 for ca coating. I put one drop on a paper towel and just spin each end of the blank on the "wet spot". I've never really had to sand it off after finished because it is so thin doing it this way, but I do anyway just to be sure. I used to get alot of problems wet sanding my antler blanks after applying the CA. My methods for applying the CA finish usually end up leaving enough CA on the ends, but in my efforts to try to put my CA on in thinner coats (for other reasons) I guess I wasn't getting enough on the ends and I started getting water under the finish while using MM and water to sand.

So wiping a very thin coat of CA as I described before wet sanding has solve the problem for me.

 

[Mr Vic]

Don't use water!!!!

Didn't think I would ever say that. A friend wants to expand his product line from Scroll Saw Puzzles by adding pens. He ordered a lathe and some supplies and I've been trying to get over to give him some pointers. Finally got by yesterday and he said a CA finish had been kicking his butt.

He pulled out the CA finishing kit from Woodcraft.:frown: I use the finish CA but was skeptical about the rest of the kit. So I walked him through how I apply the CA. Now it's time to sand/polish. I figured what the heck, we can reapply is necessary, and decided to use the kit as per the instructions....Sanded with the 400 grit Abranet, buff with the Satin polish and then the Gloss Polish...

Whooooaaaaaaaaa.... no white splatter all over, no frozen finger tips (30 deg outside) and a beautiful finish...Who would have thought it...

Might be an option..