Bronze casting is something of an art and there are several techniques that can be involved in the whole process. However, if you’re unsure as to which techniques you should use there’s always a chance the quality of the casting is effected.
The good news is we have a few tips that could help you as you learn the craft.
Keeping the Sand Moist
The sand that you plan to use to make a bronze casting must be moist. It is important as the moisture can help to retain the mould’s shape. This is vital when the sand is compacted down around your mould. Ideally, you should store the sand in a container so as to keep it moist when you’re not using it.
If you’re unsure as to how moist the sand should be you may wish to ask the person who supplies your foundry products. They will know the ideal moisture content. This will help you to know when you need to add water. You may need to do this if the sand’s moisture content drops below the level you require.
Try not to use sand that isn’t moist enough in the hope that it will work, it is very unlikely that it will. You should consider purchasing a moisture meter to help you determine if the sand is moist enough.
Finish the Molding First
When you are making bronze castings you should ensure that your moulding is finished before you light the furnace. This is crucial as it the quality of the work that you do will ultimately depend on the moulding stage and how well you dealt with it.
If you do decide to light the furnace before you complete your moulding you will have to rush things. Try not to put too much pressure on yourself while you are moulding. Take your time with it and get used to the whole process before you even consider lighting the furnace.
Assume that things will go wrong if you do rush things by lighting the furnace first. Just take your time and finish the moulding first. If you do not have time to finish the moulding you may have to leave it to a later date. Just make sure the sand is moist enough so that you can continue. Ideally, however, you should give yourself enough time to complete the moulding in one sitting, if possible.
Do Not Stir the Molten Metal
While it may be tempting for you to stir the molten metal you should try to refrain from doing so. Porosity is an imperfection that takes place when air enters the metal while it is melting. The air enters the metal when it is stirred and will do so each and every time it is stirred. While you may wish to stir the metal to ensure that it has melted and it is the correct consistency it can cause imperfections.
Do not stir the molten metal at all, no matter how tempted you might be. Allow your furnace to heat up the metal for the recommended amount of time so that it’s allowed to melt. You’re then more likely to have a bronze casting you’re pleased with.
Skimming the Metal
The surface of the molten will be covered in dross. This is where the impurities lie. The impurities naturally come from the bronze. You will need to ensure that all of the dross is skimmed off the surface. This is to ensure that all of the impurities are gotten rid of. Carry out the skimming immediately before the metal is poured into the mould. Make sure you get as much as possible. This is to ensure that all of the impurities are removed so your bronze castings have fewer imperfections.
If you use the above bronze casting tips it’s more likely that you will have better results. Start off by using metals that are easier to work with. Aluminum is a good metal to begin with as it will help you to work on your skills. If you are unable to deal with any issues that arise during the casting process you should consider speaking to a professional bronze caster.