what else but... Metal Casting with Foam

what else but... Lost-Foam Metal Casting

Fine Sand & Better Finishes

Same old foam pieces, more parts for the Lathe and CNC Mill.

I did take my time and try to get a better surface finish with 220 grit paper.

This has to be the 4th attempt at these bloody Ball Crank Handles. Notice that there are 3, all I really need is one, the second would replace the malformed Lead Screw crank, and the 3rd is a spare incase one doesn't turn out.

The sprues all seemed to be standard stuff now, follow the force of gravity.

I used as little Hot Glue as possible, incase I ended up with a cold pour.

Here are the first 2 coats of Latex in Red, the Green is coats 3 & 4. As before the paint did a nice job of filling in minor imperfections. The reason I switched colours is simply because I ran out of Red.

This is a close-up of the finish that was achieved from the multiple coats of Latex paint.

Realistically, I'll never do 4 coats again, After the first coat there didn't seem to be much of an improvement.

The Wax Dip is documented as having a positive impact on previous castings, so it is now a standard procedure when I want a cut above average finish.

This the latest addition to my Casting supplies, 60 lbs of very fine sand. I got this from a friend at work from her dad's sand pit.

This sand is just as fine as the sand I found on a northern Quebec shore on a fishing trip last year.

Along with the Latex multi-coat and wax dip I'm hoping that I can draw some conclusions about sand grade and cast finish.

Here is where the Macro Cam really shines... The sand on the left is the original mix of play and sand-blasting sand I've been using to date, the sand on the right is new Lake Dore sand.

This is another gratuitous shot of free metal that abounds all around us.

The chainsaw was fished out of the landfill, the manifold and engine casing a chum had put aside for me.

When this is done, I'll start into the half stripped GMC Jimmy behind the pole barn.

What kind of metal casting page would this be if I didn't have some shots of molten metal, and castings being poured.

As I stated in the previous page, I've switched back to charcoal. The image to right captures the pyrotechnics that is typical of foam casting.

The image to the left is from the first pot of metal that had lots of fuel and was left to just suck-up the heat. The image on the right was the second pour, hastily heated as clouds were gathering and rain was just starting to spit out of the sky. The drag of it all is that of the 3 ball cranks not one turned out.

Even though the castings themselves didn't turn-out, I was able to still gauge the quality of the finish. The image on the left is predictably the fine sand, and the image on the right is the coarse sand.

The next project to hit the list will be to build a mechanized sand sifter. I have an old jigsaw that the chuck has broken on that will be the heart of that unit.

So beyond the lousy pour, which really is not a great loss, I've finally determined a sequence that's not overly onerous to get a reasonable finish. One coat Latex paint, a quick wax dip and finally placed into the finest sand I can sift.

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