Subject: Re: Q: bronze investment splashcoat?

From: [email-masked] (MBalloni)
Date: 13 Aug 1995 04:19:52 -0400

Subject: Q: bronze investment splashcoat?
From: [email-masked] (LuBuck)
Date: 9 Aug 1995 11:49:19 -0400
Message-ID: <[email-masked]>

I am interested in eliminating more airbubbles from my bronze sculptures
(inexpensively). My pieces are 20-30 lbs.(bronze) and have a lot of
concave areas.  I need advice on how to apply a splashcoat to my pieces
(i.e. ratio of investment ingredients, how thick to make it etc...) before
doing the final investment. I don't have the facilities necessary to do
ceramic shell casting but I would like to know more about that, too.  I
would appreciate any ideas or references. THANX!

I DO NOT DO ANY LARGE SIZED INVESTMENT CASTINGS BUT I KNOW ARTISTS WHO USE
PLASTER FOR BOTH MOTHER MOLDS AND FOR SLIP CAST MOLDS AND THEY BLOW ON AN
INITIAL COAT OF PLASTER BEFORE PUTTING ON THE MAIN COAT(S).  ALSO, IF YOU
HAVE THE FACILITIES, PUTTING THE PIECE IN A PRESSURE CHAMBER (5-10 LBS
PRESSURE IS ALL THAT IS NEEDED) WHILE STILL WET WILL SUBSTANTIALLY IF NOT
COMPLETELY ELIMINATE THE BUBBLE PROBLEMS.  ALSO, THE USE OF ANTI BUBBLE
MATERIALS (SURFACTANTS AND CERTAIN TYPES OF ALCOHOL BASED MATERIALS
AVAILABLE FROM AMONG OTHER PLACES, JEWELRY SUPPLY OUTLETS) WILL/SHOULD
HELP.  CONTACT YOUR INVESTMENT SUPPLIER FOR MORE INFORMATION ON THIS
SUBJECT AND ON WHAT THEY RECOMMEND ON WATER/INVESTMENT RATIOS FOR SPLASH
COATS.  IF YOU CAN'T GET HELP FROM YOU PARTICULAR SUPPLIER, TRY OTHER
INVESTMENTS AND THEIR TECH DEPARTMENTS.  RANSOM RANDOLPH HAS BEEN MOST
HELPFUL AND HAVE SPENT RATHER GREAT DEALS OF TIME WITH US AND OUR
QUESTIONS (BOTH ON SMALL INVESTMENTS CASTINGS FOR JEWELRY AND FOR OUR
CERAMIC SHELL PROCESS PROBLEMS USING THEIR PRIMCOAT). 

THE SHELL PROCESS IS GREAT.  WE HAVE BEEN WORKING WITH IT FOR ABOUT 3+
YEARS NOW.  WE CAN MELT 85 LBS OF BRONZE PER CHARGE, AND CAN AND HAVE
POURED THIS AMOUNT IN ONE PIECE.  NORMALLY WE POUR 10 THE 25 LBS PER
PIECE.  THE SHELL PROCESS USING R&R'S PRIMECOAT IS VERY SIMPLE, REQUIRES
VERY LITTLE IN THE WAY OF TEMP./HUMIDITY CONTROL, THE SHELLS ARE STRONG,
GIVE GREAT ACCURACY AND DETAIL.

WOULD BE GLAD TO ANSWER ANY QUESTIONS, GENERAL OR SPECIFIC AS TO SHELL
MOLD PROCESS OR ANY OTHER AREAS DEALING WITH BRONZE/ALUMINUM CASTINGS.  I
AM JUST GETTING INTO SAND CASTINGS FOR COST CONTROL WHEN POSSIBLE.  I LIKE
THE SHELL BEST FOR DETAIL, COMPLEX SHAPES AND ALL BUT IT IS RATHER LABOR
INTENSIVE IF A SIMPLE PIECE CAN BE SAND CAST.

ANY ONE INTERESTED IN DISCUSSING RUBBER/SILICON MOLD MAKING, RUBBER TYPES,
MATERIALS FOR MOTHERS, METHODS OF GETTING WORKABLE SIZED WAXES FROM RUBBER
MOLDS OF LIFE SIZED PIECES??  ALSO PATINATION, AND BASES.  SOURCES AND
RESOURCES, LIKES AND DISLIKES OF ALL OF THE ABOVE!!

LOOKING FORWARD TO SOME EXCHANGES OF INFO.

JOHN
MAIDEN METALS
DIV. OF MIDLIFE CRISIS ENTERPRISES 
po bx 44
philo, ca  95466