Had a hella day yesterday. Didn't start off that fast but by the time the sun was rolling over the horizon, I was beat.
Helped out cutting down some lightening struck trees, did some yard work, cooked lunch, ran to 'The bigger city' up the road to hit some stores for stuff we don't have local,
Then,
THIS.
First up, I was working on this yesterday and the idea I started with, while sound on paper, failed completely due to humidity issues. Those that have worked with wood will know well, just how quickly thin wood can warp under high humidity conditions. (especially when you are cutting intricate shapes crossgrain.)
This pick shows how bad that warp is. It looked great for about 3 hours then started that silly creep thing. Even under clamps, the center hole started showing distortion from circular to ellipsoid.
SO, Back to the saws and a different idea today. I also decided to hell with that hole in the middle as it makes for a more complicated mold. That's why I have a 3-1 machine, right? To make those kinds of holes in things (among other kinds of changes in structure.)
Here are the patterns in progress. The triangular shaped one gets the hole filled with bondo a little bit after this pick was taken. (Seeing how I am alone while doing these things, I get into a groove and all thoughts of camera go out the window. I am trying to get a recorded history here; I slip though.)
Here are the finished patterns. I did something a bit different this time around. (inspired by a product seen on a shelf somewhere) I did all the usual things, Clean up rough spots, bondo holes, sand smooth as a babies butt, and primer with filler primer. I went one step further though. The last coat of primer went on after I was satisfied that there would be nothing to hang in the mold. BEFORE it dried, I dropped it in my box of Plumbago parting dust which is 95% raw graphite. I use the parting dust liberally as it is, but thinking that a graphite coating that wouldn't 'rub off' would do even better. (results later in the article.)}
Time to pound sand!
(in my world, that ain't a bad thing, LOL)
I could show you the process of packing a mold, removing cores and patterns, setting the cope and drag, etc etc etc. It's really kind of boring until you go to pull the patterns out but that means My attention is 100% on doing it right; Pictures are really not a thing on my mind.
So, things went well with pounding sand, time to invite Lucifer into the game. As you all know doubt know, there's a heat wave going on. Call me crazy but when the mold came out as nice as it did, thanks in no small part to that new technique I used; hell, I was inspired to melt metal. Un-Godly heat index or no. (rain would have stopped me though)
And Lucifer did well. I had 12 pounds melted in less than 45 minutes, ready to flux and pour.
I did get a bit sloppy and there was a spill and a small fire on the flask. No big deal. I am still getting used to using the large tongs to handle that crucible. You don't improve by sitting idle doing nothing. And this is a risky hobby at its best (and deadly at its worst) No burns on me and I didn't burn down any buildings; Guess thats all that matters right?
The moment of truth.
Looks good, still hot enough to be smoking.
The end result in front of the new patterns.
And here, I am hand working the two parts to match each other.(that is an old table saw plate, covered with plate glass and bondo, and I use a spray adhesive to hold the sandpaper in place. Cheap and highly effective for achieving a truly flat surface)You can see that even with great castings, there are still imperfections to deal with. Still, I am absolutely stoked on this pour. This is quite literally the best casting that I have done EVER! When I go to face off the crankcase, I won't have to take more than .010" . Thats HUGE to me.
Now, I have to make the cylinders, the crankcase faces, the heat exchanger, and the mounts to attach it to some piece of wood I conjure up. (walnut looks good with aluminum and brass) And of course, machine and hand fit all the parts AND make it work. Thinking I will add a pulley and and a 'dynamo' and light just for grins. (just like I were in school doing a science fair or sumpin. LOL)
Wednesday, July 13, 2011
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1 comment:
Cool! Or hot? : ) You want some wood warpage, c'mon down my way, ha ha. That's okay, boat builders are "twisted", and make use of stuff that would give a framing carpenter a heart attack...
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