blanks exploding

[Lestergillett]

I am a new penturner and have trouble with the blanks spliting when
i am turning. I also have had the ends at the bushing chip out and
have to make a new blank to go with the outher one. What do you all
do to keep this from happing ? The wood that is giving me trouble is
spalted sycamore and zibra wood.

Lester

 

[TellicoTurning]

Lester,
I don't have any experience with the sycamore.. but zebrawood will split if you get too aggressive and if your tools aren't sharp. I used to have trouble with that, and sometimes on the acrylics I still do, but if you are moving your tool from the bushing to the wood, you'll more likely split out the end.. try moving from the wood towards the bushing, with light light cuts and sharp tools.

 

[KenV]

Are you using thin CA to reinforce the soft chipy wood?? Is the zebra wood cross cut? Are your turning tools scary sharp with a hone? Have you soaked the end grain on the spalted sycamore with thin CA before and after you trim with a pen mill or sander?

If the answers are not yes, you have an opportunity to get ahead of the wood. I get some chipping occasionally, especially with spalted wood. Cross cut zebra can be a real challenge. Tools that are not very sharp tend to chip and chunk much more than really sharp tools. I am a diamond hone and skew user for finish cuts.

 

[LEAP]

I had a few pens blow out when I first started a few months ago and when I took a good look at them I found that they blew out where I did ot have a good glue bond betwen the tube and the blank. Coating the inside of the blank and the outside of the tube seems to do the trick. Since I started being much more carefull with the glue the blow outs have stopped. The ends at the bushings were also giving me some troubles on some woods until I sharpened the barrel trimmer with a diamond stone. On softer woods I soak some thin CA into the ends before trimming. I think I was damaging the fibers with the trimmer causing the chips at the bushings.

 

[Lestergillett]

thanks guys. The zeberawood was cross cut and it had some bad spots
in it. that may have been why it split out. I try to keep my tools sharp and this is one area i am still working on to sharpen my tools.
i do have the oneway jig and finely have it set up like the artical
in the AAW magazine. it sure made a lot of differance.

On glueing the tubes do you use some kind of stick to spread the CA
down in the blank and the tube? I have have been just putting the glue on the tube and side it back and forth in the blank a couple of
time then center it and let it dry. I do enjoy making pens as it is
quick and gives me some idea to git to frends and coworkers.

Lester

 

[martyb]

Another thing to try is to loosen the nut on the mandrel a little after you get the stock roughed round. The pressure from the nut on the blank will blow out the blank in a hurry once you get it down close to final shape.

 

[LEAP]

Lester,
I use some craft picks I picked up at Micheals to spread the glue in the tube. Then I put some wax in the tube to keep it from picking up the glue on the way through. Just scrape the end of the tube across a block of parafin then tamp in into a plug with the butt end of a drill bit.

 

[LostintheWoods]

Ditto to Marty's suggestion.....It's improved my ratio tremendously since I first became aware of it. And the CA coating will be very beneficial, as well.

 

[airrat]

Another tip is sand off the corners of your blanks before you turn. This will take some of the stress off them from the initial rounding. On Acrylics, crosscut and some not so common types of material, I have done this and it works great.

 

[Paul Downes]

I use gorilla type glue and I think it may provide a little cushining because of how it foams. I also soak CA into the ends of spalted woods-sometimes even when I get close to the end of the brass when milling the ends. Ditto for cross-cut and palmwoods. Ditto on sanding the corners off. Snakewood always gets this treatment.