"How to repair & prepare a wax, prior to casting"

In my just posted technical essays is a rather easy project to work on. I’m showing how 2 waxes that were wax-injected for me, both had/have many errors or misadventure to each of them. During this essay, I showed how easy it was to repair each wax.

During this writing, I added that certain rules should be followed to be a successful wax repairperson. This alone could be a rather interesting sideline to add to your business. I just posted 42 photographs and I could have added more but that would be too much reading & viewing.

Go and have a good look at these nice up close photographs. I have inserted text for each photo…have fun and above all, learn!


This essay will educate YOU to better understand the many techniques in the preparation and improving a wax-form, prior to casting.

Many of you have your own rules and methods! These are solely mine and they have been giving me many years of good results!

Here is a ‘vulcanized rubber’ mold that I use often in my demonstrations. You can see the “Sprue” leading from the inside of the heart-shaped pendant, to the wax injection-opening.

I feel that I must remove the internal sprue area for me to gain better access in modifying the inside of the pattern. I will re-attach that inside sprue again!!!

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There are little lines cut into the rubber to allow any air can be allowed to escape while the hot wax is being injected. (These cuts in the rubber are so small, but they are there!) I will be keeping the long-sprue attached for my caster to put each pendant onto a ‘wax-tree’, as this is very important in his many casting processes.

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The first question is how do you remove the wax form? The answer is so easy, I’d like to let the wax slowly cool, but not harden, it still has to be released, but not allowing the wax to break!

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This maneuver is very ‘delicate & simple’, just bend the ends down with the aid of your finger-tips as shown and the wax form will literally pop-out! There will be some little rubber spots still clinging to the wax, just ‘slowly and carefully’ release these spots as you take the wax out of the rubber.

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With aid of a ‘wax-heating pen’ start to put some extra wax inside the frame . I found previously that the thickness of the metal was lacking and the only solution was to add much metal where the stones will be set! But the inside sprue is going to further hinder any modification, but these must be removed for easier access .

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Already you can see some difficulty starting with the inside-sprue . I have no possible chance of fulfilling the “adjustment” that is so desperately needed.

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When I’m holding the wax, I carefully & lightly use my finger just for support, any bending of the wax can be a problem. Here you can see where the "sprue’ was removed!

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For this pattern I’m completely closed off all of the setting holes . I’m going to completely change the overall appearance further on! I prefer to use a different coloured wax as I must see just where the new wax is being placed.

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Already you can see where the wax is being placed, If I used the same wax colour, I’d have just no idea where this new wax is being applied!

I’m reinforcing and making the inside-frame much thicker to allow for better setting practices.

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I’m really redesigning the whole top of the heart-shape, all of this can be easily done in the wax form, not in the silver pattern (after casting)!

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Here are the “before & after” fixing, but look, I missed a spot…OUCH! If I used the same colour of wax, I wouldn’t see the hole, interesting process isn’t it?

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After I plugged up the many 22 setting holes with wax, I can see that there are more spaces that need to be repaired…" back to the drawing boards !" I have 16 of these wax pendants to modify and it has taken me many, many days to observe each wax and do multiple repairs to them all.

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Imagine if I had the “inside-sprue” still attached, what other problems would I be running into? I think that there would be many!

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I’m using a 'Wax-Carving" file to smooth the ‘repaired’ surfaces.

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After I use the rough textured file, I use a #400 grit Emery paper to make sure the surface is smooth!

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There are still some minor defects in the new wax surface . I prefer to do this ‘fixing’ now and not in the silver casting. Those little black spots are just pieces of dirt and will become pin-holes afterwards!

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Just observe how many errors there are, I’m now counting 14 and this is on just one of the 16 wax-pendants that I have to carefully modify!

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I’m now using my #240 grit Emery paper, as this one pendant is now finished. I attached the inside-sprue…(15 more to repair.)

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Now you can see where the setting holes have been filled in!

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The inside of the heart there is a real ‘mess’ of missing sections for bead-setting. I have to now repair every one of them. So easy to do this with a wax-heating pen, imagine if I had to do this in silver, with time lost and cost of the silver-soldering…It would be too darned expensive…:>(

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Another section that must be filled-in and re-drilled. I’m actually redesigning the pendant pattern right from the start. If I see that there will be setting problems, then this is my only chance to rectify the many problems that might & will occur.

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I’m now going to fill in all of the setting holes. I do this from underneath & inside and of course on top!

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The wax got bent by accident, but don’t be too concerned! All I did was to place more wax into the bent area and filed it smooth. But how did this happen? Easy answer! The heat of my finger-tips warmed up the wax and it slowly got out of shape!

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I heat up the wax-pen tip, as I need to have all of the remaining wax burned away. All I do is to heat up the point ‘red hot’ and let the wax burn off! I really need a ‘clean & usable’ pen to work with.

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I now going to reattach the ‘inside-sprues’. I must observe that all of the joints are evenly formed and thinking of the melting silver and how it’s going to flow in the investment during the casting process.

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I prefer to have more wax instead of just a little at these important joints!

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This wax form is ready to go to the caster…a.k.a ‘finished’!

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How much will this finished wax weigh in silver? Multiply the wax weight (.07) by 11 (estimated wax => S/S) this now gives me a number of 7.7 grams for each heart pendant. Then again multiply to get the $ 3.00 cost per gram and the final number will be $23.10 (CDN funds)!

All of these numbers are not including any additional connecting ‘Sprue’ waxes. (As I give many wax castings to my caster, I get a monetary discount, but we won’t discuss this here!..:>)

I now have 16 new heart-shaped waxes ready for him to cast!

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With the additional wax-sprue and more ‘modifications’, the weight has been increased. The cost is now at $29.70 (CDN funds) . REMEMBER, " wax weight times 11 " is an (estimated) silver-weight!

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Here you can observe just why I had to increase the metal thickness . Otherwise, I couldn’t even think of setting any diamonds or any size of gemstones by using the (original) wax frame.

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Here is a ‘partially’ finished "Fish-Tail’ setting applied to the heart-shaped pendant.

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This is why you should be very observant in examining any wax you are working on. Be very sure that there are not particles of dirt sitting in any part of any wax that you are preparing for casting.

Upon closer examination I found that this particle of dirt was actually piece of yellow gold that got caught in the wax that I was preparing. Can you imagine what would happen if this got cast, it would be almost impossible to remove afterwards…OUCH!

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I nearly missed this piece of metal that got stuck in the wax!

Important lesson learned from this essay? Be very diligent and explore any possible chances of making errors in cleaning your waxes. "The time saved here will save you much more time after the casting!"

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