Being somewhat of a novice to Polyurethane resin casting. I have learned a great many things. This is of course AFTER screwing a casting up.
The mold is over 18" long by 8" wide. Trying to pour resin through two fill holes while trying in vain to fill the mold up. Messed up three crane girders this way. Instead of completely scrapping them. I wound up keeping them.
That was a month ago...
My Wife a month ago when this resin casting endeavor started. Quicky figured out the problem and told me.
Fill one side of the mold up,let it set. Then later ,pour the other side and set the cured side on top. Simple right ?
Didn't listen to her a month ago.
Tried it yesterday.
It of course worked to perfection.
Eating Crow as we speak.
Figured you guys would get a laugh.
Fear an Ignorant Man more than a Lion- Turkish proverb
Modeling an ficticious HO scale intergrated Scrap Yard & Steel Mill Melt Shop.
Southland Industrial Railway or S.I.R for short. Enterchanging with Norfolk Southern.
RR_Mel I‘ve never tried making a casting that large and most likely never will. I have one question, how did you do with air bubbles in your casting. That’s always the toughest part of casting for me. Thinning the resin with Acetone helps the air bubbles but some times it makes the casting too weak. 10% Acetone lets the air bubbles rise faster but weakens the resin. 5% Acetone takes care of the weakness but only helps get rid of air bubbles. The 10% Acetone works great for HO scale figures and small parts if strength isn’t a requirement. Anxious to see some pictures of your structure. Mel My Model Railroad http://melvineperry.blogspot.com/ Bakersfield, California I'm beginning to realize that aging is not for wimps.
Hi Mel,
These castings have plenty of bubbles. I guess I've been pretty lucky not to have a real problem. A little Squadron putty in spots & done.
Luck & two minute Polyurethane resin set time. Don't have time to degass bubbles .
Gonna cast four more beams,then the Basic Oxygen Furnace can be built. The outside overhead craneway will be painted silver & weathered.
That's the plan at least...
Patrick
My wife is very good at finding a better way of doing things when she sees me having problems.
.
I need to get better at admitting she is right.
-Kevin
Living the dream.
I know that crow flavor all too well. Just one example, I needed a power steering unit for a Dodge Van. We had an old Valiant for spare parts for a nicer one, if ever needed. My wife asked if the unit from the Val would work on the van, both being Mopar. "Oh, Honey, that's so cute"
I figured the '82 3/4 ton van would surely have a heavier unit.
At the junk yard, not so near to home, I told 'em what I needed. The guy at the counter tapping on his keyboard, mumbled something about a Dodge Aspen, and a Volare as a match. (Uh-oh moment) "Um, could you by chance run a '75 Valiant (as in, sittin out in the back yard) number for a match? ... Uh -Huh. Well, I couldn't hide it from wifey cuz she needed to know how much the check was for the checkbook record; Zip.
So I'd wasted half a day, AND got to go home and eat crow. And she didn't mind feedin' it to me. Plus my best mechanicin' buddy was right there at the junk yard counter with me also to witness the embarrassment.
More on topic though, yeah, lets see some pictures of the crane progress? Dan
For getting rid of bubbles in castings, I use a small butane torch. Passing it quickly over the surface draws the bubbles to the top and breaks them.
Mark.
¡ uʍop ǝpısdn sı ǝɹnʇɐuƃıs ʎɯ 'dlǝɥ
Totally not on topic, but still relevant, there is a youtube channel called The King of Random, and he uses a vacuum chamber to get rid of bubbles before pouring the casting material (and the mold too, for that matter).
I'm beginning to realize that Windows 10 and sound decoders have a lot in common. There are so many things you have to change in order to get them to work the way you want.