Reduction?

[doesdoes]

Can anyone help me out? What does reduction mean? How does it work? I'm still very new to lampwork. There is so much to learn, but I love every minute of it :smile:
Jenny

[pam]

Hi Jenny, Welcome to our obsession. A reduction flame is a flame that has more propane than a normal flame. On an oxygen/propane torch, if you turn all the oxygen off and hold your bead in a pure propane flame,the bead will turn black because a layer of soot will build up after the bead goes below the stress temp. However, adding just a little extra propane to the flame can make certain glasses, called reduction glasses, do beautiful things. Reduction glass is called that because when exposed to a reduction flame, the metals are brought to the surface of the bead and you get a very metallic finish.

[doesdoes]

Thank you so much, Pam :razz: I'm so happy with this site. You ask a question and very soon you get an answer. A great help to lampwork-beginners. Thank you again :grin:
Jenny

[Coffeebean]

Pam,

I purchased some reduction frits and have been trying (unsuccessfully) to use them. I cannot get them to reduce and it is making me so sad! They just turn out muddy. Or if I do get some shine it is so slight my boyfriend insists it is just the shine from the glass and it really didn't reduce :( At any rate, any thoughts on what I may be doing wrong? I work on an oxy/propane minor burner. Thank you!

[Kevan]

Coffeebean, are you turning the propane up so it's yellow and then flashing the bead in and out? If you cook it too long it can go muddy. Also it has to be the very last thing you do to it. Don't put it back in an oxy flame or the metallic finish just disappears.

This goddess I made with all Iris Gold reduction glass. At the very end I turned up the propane, waved her in it a few seconds is all.

http://i36.photobucket.com/albums/e36/oobeads/irisgoldgoddessback.jpg

[one-eared pig]

I am on a HH with Mapp gas, and i actually achieved a reduction look with inense black(moretti) and raku frit. i was following the adice of many to super heat and then cool (i use a brass marver in ice) the raku, and after the bead came out of the kiln, it had the metallic shiny reduction look. sometimes you never know what the bead fairy will bring!

[Coffeebean]

Kevan that is GORGEOUS!

First I was turning the oxygen completely off, and flashing it in a propane only flame. Then I tried just turning the oxy down and the gas up so it was a big yellow flame, but still had some oxygen. I wonder if I am flashing it for too long - it sounds like that may be at least part of the problem. I will try doing it for just a few seconds as you said, and see what happens.

Is it possible my ratio of gas to oxygen in the flame is not correct too?

Thanks so much for your help!

Melissa - I don't really understand the ice process you are referring to. I am assuming you cool the brass tool in ice water, melt the raku through, marver it on the icy tool, and then flash it in the yellow flame to reduce?

Thanks everyone :)

[pam]

First of all, the amount of propane needed to get a reduction is different from glass to glass. Most reduction glass does better if you just add a little more propane to the flame than normal - definitely not a big yellow flame. Try making the yellow part of the flame around 3 or four inches long. Just gently slip one side of your bead into the flame and then out. Turn the bead a little and then gently in and out of the flame. If you don't get reduction, then add a little more propane. It's hard to tell you exactly how much because the flames vary from torch to torch and from glass to glass. Do some experimenting - small beads first just until you can get the reduction you want.

[JanMD]

<<<What does reduction mean? How does it work?>>>

From Lampworking Lingo at Northstar Glass -- (http://www.northstarglass.com/glossary.asp) -- "Reducing: An atmosphere that contains a large quantity of uncombusted fuel that can cause the oxygen molecules contained in the metallic oxides that color the glass to react. This can cause a metallic deposit to appear on the surface of the glass."

From the Glass Glossary on the Corning Museum of Glass site -- ( http://www.cmog.org/index.asp?pageId=689#P18) -- "Reducing atmosphere -- An atmosphere in a kiln or furnace [or in a flame] that is deficient in oxygen. Sometimes, a reducing atmosphere is created deliberately to reduce oxides to their metallic state, as in the case of luster pigments."

From Bullseye's Torchtips in the working notes for their "lustre" glasses, also called reduction glass. The same plan of attack can be used when working with reduction frits -- ( http://www.bullseyeglass.com/connection/education/torchtips/index.html) -- "When you are ready to develop a metallic sheen, the glass should be relatively cool (no visible heat) and stable on the mandrel. Create a reduction atmosphere by turning the propane (fuel) up and while passing the bead through the flame, watch for the surface of the glass to become metallic. The lustre surface develops readily on cooler glass and can vary greatly depending on the length of time spent in the reduction atmosphere. Once this has happened, the piece should be put into an annealing kiln (in other words, this is a finishing step). If the metallic surface is reintroduced to a neutral flame, it will dissipate. It can be brought out again by returning it to a reduction atmosphere."

"Reduction" is the creation of an oxygen-depleted atmosphere (in our case, inside the flame) by turning the propane up.

Hope this helps a bit!

JanMD

[Emily]

You might not want even a few seconds in the flame. Try just one second at first. Turn down your oxy or turn up your propane, give the bead a quick turn in the yellow flame, and take a look.

[doesdoes]

Thanks everyone :waving: I'm going to enjoy trying out all your tips :razz:
Jenny

[magpiedreams]

Hi,

I have yet to try reduction but bought some small sample packs a few weeks ago. The salesperson (The Vinery in Madison, WI - very helpful folks) also gave me a length of thin foil (takes the high heat) and said to apply some foil over several of the small oxygen holes on the end of the HH torch as with MAPP gas there is no way to adjust the ration of oxygen to gas. So a manual closing of a few of those holes is a work-around.

I'd think a quick in and out with the HH would also apply since the flame should also change to reflect less oxygen.

She suggested some trial and error so it sounds like this is the case with the other torches using a mix of oxygen and fuel.