What are these black markings?
 

Can anyone tell me what these black markings are and why only some 104glass is afflicted?

I’m relatively new to Lampworking but have been fusing for a while now.

I think this is caused by scum coming out of the torch??!!

I’ve recently bought the effetre opalino glass and they are all very susceptible to this discolouration. Any one else found this to be the case?

Any help would be very much appreciated 😊

I think Effetre opalinos are notorious for that, being very sensitive to the gas. I am not sure how to avoid it. I was advised to learn to love it if I was going to use many opalinos.

What torch are you using?

You may need to move your bead further from the torch head. Or add more oxygen.

Yes, it looks burnt. Work cooler, and less propane rich if you have a dual fuel torch. If not, move out in the flame, where more propane is already burned and there is less left in the flame.

yes the opalinos and alibasters (sp?) burn easily. That is burnt glass, too hot, too long or too close to the torch head.

And I will add that the fuel takes an inch or three to burn once it leaves the torch face so you might be working too close to the torch.

You don't mention the kind of torch you are using but that picture looks a lot like my hothead torch work when I first started where I wound up capturing unburnt fuel in the glass.

Took me a long time to remember not to creep up on the torch.
My body just kept up with the habit of "closer is hotter" which is not true but it sure seems like it should be.

Thank you everyone for all your advice. I work on a minor torch on a 5lt oxycon.
I think your all correct in that I’m working far to close to the tip of the torch. But these opalinos are extremely sensitive to picking up discolouration from unburnt fule..... sigh!

Is it worth continuing with the colours that the question!

When the colour stays true they make rather lovely hollow beads 😊

Once again thank you all very much for the advice.

Kindness

Tasha.

For me, it's all about figuring out stuff with my mind .... Which takes long enough in it's own right.

And Then trying to teach my body how to use what I figured out with my mind ..... without forgetting what my mind figured out.

And THEN playing with the glass while pointing myself toward that nebulous end point that I - think - I wanted to achieve.

All the while reminding myself that the destination really isn't the goal.
The goal is the journey to getting to the destination.

And I realize I have drifted back too close to the torch face again.

:roll:


Its a good thing I like playing with fire and molten glass.

I think that it is worth practicing, but don't know, because I haven't spent that much time with them myself, LOL.
But I think if you can remember to go slow and keep it cooler, that you will have success.

The opalinos can be very lovely, when worked correctly, but they are a bit tricky to start off with. Do you have any other glass you can practise on?

Heat control, torch settings and where your bead is positioned in the flame can all make a big difference!!

Keep at it, it is sooo worth it ;)

Tasha, you can try CIM opal colors like Crocus, Jelly Bean, Chalcedony, Plum, etc. You can find a lot of feedback from the testers for each color at CIM site. CIM opals are more forgiving and do not burn easily. Some become opaque in the kiln, like Poison apple, but layering over clear may help to retain the translucent appearance.