Wax / techniques for making sprues

[lobby]

Folks,

I pretty much always design sprues into the 3d models. Like this:



That way, all I have to do is melt wax onto the base and place my prototype in the wax.

I've seen here that some of you actually create wax sprues, they way you do with wax (not resin) models. Every time I try to do this (I only have that blue wax in the pic), the wax will not stick to the resin.

Can y'all please advise as to how you do that? Is there a technique I'm missing? Am I using the wrong wax?

Thanks!

[mwm]

I use "Ruby Red" injection wax to weld my B9 models to sprue wax. I use red sprue wax as well as yellow and blue sprue wax. I've been spruing printed models from various printers for a ~decade. Ruby red works fine for me.

[rkundla]

I use the yellow sticky wax pellets from Rio to attach wax sprues to my resin prints.

[Robert Howle]

I use the blue a lot myself. put a small amount of melted on the model first, then attach the blue sprue.

Robert

[danmr]

I have the exact same blue wax, and do as Robert said, I will only add that for heavy models like graduation rings, I will melt a ring of wax at the joint, for extra support, and never had a problem, I do have notice that if you try to straighten the model, a small break will form but as I use a wax pen I will do a quick touch up and is ready to go.
Something to take in consideration is that I use a vacuum casting machine to do a boil. And like I said I have not have anything come loose.

[erikgem]

I make rubber molds for different sizes of sprues. Also for special shapes (not shown in picture) Then I inject with my regular injection wax. I have no trouble attaching.
Dave

sprues.jpg (72.29 KiB) Viewed 3547 times

[Metalcaster]

I also make my own sprue wax in many different sizes and shapes... I made molds on all of them so I can inject as needed in any wax.
For me, the most important thing to do is to melt some of the wax onto the print , then use the wax welder to move it around a bit and get it to really bond to the b9 print material... then I weld the sprue to that area,,, have not lost any pieces due to sprues coming loose since I started that quite a few years ago.

[lobby]

I also make my own sprue wax in many different sizes and shapes... I made molds on all of them so I can inject as needed in any wax.
For me, the most important thing to do is to melt some of the wax onto the print , then use the wax welder to move it around a bit and get it to really bond to the b9 print material... then I weld the sprue to that area,,, have not lost any pieces due to sprues coming loose since I started that quite a few years ago.

That's generally what I figured out in the past few days. The problem I was having was a technique issue, not a materials issue.

Controlling the temperature of the wax pen (low is good, to prevent the wax from flowing uncontrollably) is important.

Thanks to all the advice here, I was able to attach some wax sprues to my emerald models

[Franz]

Folks,

I pretty much always design sprues into the 3d models. Like this:



That way, all I have to do is melt wax onto the base and place my prototype in the wax.

I've seen here that some of you actually create wax sprues, they way you do with wax (not resin) models. Every time I try to do this (I only have that blue wax in the pic), the wax will not stick to the resin.

Can y'all please advise as to how you do that? Is there a technique I'm missing? Am I using the wrong wax?

Thanks!

Hi Lobby

Here are my thoughts.

You need to clean your rubber sprue base better to leave no investment down to rubber or wax.

I build all my sprues and feeds in cam when i can. It saves time and has made me a better caster after 30+ years.

As for bonding a print to wax, it is very easy. Use sprue wax with a high setting on wax pen, put some melt on the end then place around the seam. I use a loop these days to insure there is a good flow.

How this helps and a very happy thanks giving
franz