Blank drilling for dummies (me)

[JeffW]

I'm accustomed to turning wood blanks or opaque acrylics but have created a brick wall for myself with PR blanks. Not painting the hole is not an option (the obvious).

If I drill what I think is the recommended size I encounter problems with tube insertion and scratches in the paint. If I drill oversize there is a gap at the end between the tube and the blank. Using q-tips I've tried Testor enamels and 24-36 hours drying time. I've also tried craft acrylic paint allowing the same drying time. I've used a chainsaw file to help make sure the inside was smooth before painting. 5 minute epoxy is my glue of choice at this time.

Any recommendations to help me improve will be greatly appreciated.

 

[skiprat]

I use the acrylic paint with a Q-tip. Paint the hole liberally. Before the paint dries, I push the tube through and twist it around a fair bit.
Take the tube out and wipe the paint off the tube. Do it a few times till there is very little paint getting on the tube. Give it 20 mins or so to dry and then I CA the tube in. :wink:

 

[U-Turn]

I use Krylon spray and have not run into any issues so far.

 

[NewLondon88]

I've had good luck spraying the tubes with primer first. Paint might
come off or scratch. Primer won't. (works well under labels, too)

 

[JeffW]

Holes ... not tubes

Should I be painting the tubes also? As of now I'm just painting the holes.

 

[KenV]

Jeff -- I also use 5 minute epoxy for short runs and have not faced the challenges you are experiencing. I use polyurethane glue when I am making a large number of glueups. I plug the end of the tube with dental wax sheet and have the blanks a bit long at glueup so there is 1/64 to 1/32 at the outboard end and near even at the middle where I want the patterns to match.

you only need about 0.005 (also called 5 mils) of paint to cover heavily and 1/2 that should be adequate. Pools and puddles do not help and add to problems. Before paint and glue, the tube should freely move but not be rattling around either.

Spraying the tubes with primer suggested by Charlie is a good practice - as is the use of precoated tubes - the coverage needs to be predominate but it is ok if it is not perfectly 100% coverage.

I coat the inside of the blank with epoxy -- a bit spread around the insertion end of the tube and get it going in with a twisting - corkscrew motion to move the glue around for best coverage. there should be a bit in the edge of the insertion end of the tube as it moves forward and a small bead around the blank at the middle insertion end. when the blank is very slightly proud of the end of the tube at the middle (match end) I have extra glue at both ends (no gaps as you note) --

5 minute epoxy sets in a few minutes so I use a Exacto nive to cleanup the excess once it has gone "rubbery" because it is easier than working with the hard stuff.

Are you starving the glueup -- your comment on gaps at the end suggest you are not being generous with epoxy.

 

[fernhills]

You can also tint the epoxy with the same paint you are using....Carl

 

[Frank Nemke sr]

I sand my tubes and hang them on wires ,then spray them with .97 Ct wal-mart spray paint. Works for me

 

[Dan_F]

I have used either spray paint or Ceramcoat acrylic, painting the inside of the blank, not the tube. I usually do two coats, then let dry overnight. I use 5 minute epoxy. The acrylic pearl colored paints work well, and add a little something extra for when the light penetrates all the way through the blank. I use a Q-tip to paint with the acrylic paint. I always paint the blank, because otherwise any glue bubbles that form may be visible in a transparent area.

I drill on the lathe - this can be done after the blank is rounded, and held in a collet chuck. or before rounding, held in pin jaws of a scroll chuck, or the special drilling chuck or jaws from PSI. I have a Vicmark chuck with pin jaws that function like the psi drill chuck, and have just started using that instead of the collet chuck, which saves a lot of time. I cut the blank in two before drilling. I also leave enough extra length in the blanks so that I don't have to drill all the way through. This can sometimes result in blowouts. I cut off the extra on the tale saw after drilling. This works much better for me than using the drill press, as there is more runout with the press, and quill wandering, which can lead to that widening of the end of the hole you were referring to.

For gluing, one more thing that helps is to set your blanks on end after gluing the tubes in. This will help keep the tubes more centered in the holes than if you lay them down on their sides. They may settle down to the bottom of the blank, and you may have to push them back up a little now and then until the glue sets. This all depends on how much bigger the hole is than the tube, and how stiff the glue is.

Dan

 

[JeffW]

Thanks - I knew I came to the right place

I'll make some adjustments to my process and expect improvement. Thank you to everyone for the suggestions and comments.

 

[clapiana]

Painting is a pain I tried using indy pen's brass tarnisher for the 1st time yesterday which seems ok but your selection in color is black or black or black