I've got Blackberries!

[metalhead]

Well, I decided to try and roll some stars and they keep coming out looking like blackberries. I don't think it is because the lead shot clumped together. I made sure that didn't happen. They started out round but once they started getting bigger than a quarter inch or so they began looking more and more like blackberries. Not sure what's going on here. Any ideas?

[Weasel]

You need to simply spray your stars with water and let them roll for awhile without adding any more dry powder to get rid of the blackberry texture. Skylighter came out with a newsletter on this problem about a week ago.

 

I have never rolled stars long enough before my star roller breaks down to experience this . I really need to work on that thing....

[metalhead]

Yea I tried doing that. How long do you have to wait? I waited a good 5 minutes without adding any comp and it didn't improve much. I'm curious as to what causes it in the first place.

[Peret]

I'm curious as to what causes it in the first place.

I would guess it's the same reason that my cut stars tend to come out with projecting corners and concave faces. Once they pick up small lumps, they tend to roll on the lumps and pick up more prime on them, while the rest of the surface is held out of the comp. There was a mention of this in AFN years ago, though I don't remember if they came to any conclusions. It probably doesn't happen if you have several kilos of stars in the roller, as seen in Japanese videos, as they would tend to "mill" themselves round.

Edited May 29, 2010 by Peret

[ExplosiveCoek]

You need to simply spray your stars with water and let them roll for awhile without adding any more dry powder to get rid of the blackberry texture. Skylighter came out with a newsletter on this problem about a week ago.

 

Where can I find that newsletter? I haven't seen any new one's coming from them for a year now..

[metalhead]

It probably doesn't happen if you have several kilos of stars in the roller, as seen in Japanese videos, as they would tend to "mill" themselves round.

 

Yea I was thinking the same. Next time I try to roll I'll add more shot and see if that helps.

[FREAKYDUTCHMEN]

A couple of things might help;

 

Don't roll them too wet, they can get too sticky with too much moisture.

Use 50 alc / 50 water in your spray bottle.

[swervedriver]

Freaky, does 50% alcohol effect how strong dextrin binds? I was always afraid to go that high.

 

fwiw, It depends on the composition, solvent, etc, but I've never had luck rolling them back to round once the raspberry problem starts the way skylighter describes. I suspect rolling small amounts of stars (less than a pound)doesn't have the combined weight to smooth them out as much as larger amounts of stars do. It could be the shape of the roller barrel has an effect on this happening too. A deep narrow barrel vs a wide shallow barrel, etc. I've let them roll so long trying to smooth them out that the comp starts to come off the stars and stick onto the roller walls, shrinking the stars.

 

Probably 100 different answers, but for what it's worth, the only way I've found to fix them is to take them out, dry for a several hours or a day, then roll them in a thinned-out toro paste of the same comp or toro prime with the same binder/solvent if sized correctly. Then they get somewhat round again. Comps high in airfloat charcoal like tigertail and willow tend to do this. They are just much more difficult comps to roll than glitters for example...

 

BTW, raspberry stars work fine, they just look ugly and you can't fit quite as many in a shell. I'd just size them up and shoot 'em as-is

[FREAKYDUTCHMEN]

50/50 is no problem, stars also dry better with the 50/50 solvent.

[metalhead]

hey all, I just tried my hand at rolling again with some D1. Also, I used a different spray bottle to see if that helped annnnnnd it did. My new spray bottle sprays more of a mist rather than a...spray. My thinking is that with larger water droplets coming from the sprayer, you get spotty coverage on the stars. Once a bump forms on the star it grows and grows until it has more buddies and they quickly take over and start a bump colony...

Eventually I'll try rolling some of the same stars as I did before to see if the sprayer was the culprit.

Edited June 10, 2010 by metalhead