Mark Buchler (m_buchler) presents us his first (and hopefully not his last) article for Aeroscale: Making resin parts. Explained like that, it seems very easy! Thanks a lot Mark!

Link to Item

If you have comments or questions please post them here.

Thanks!

BUGATTI! BUGATTI! BUGATTI! BUGATTI! BUGATTI! BUGATTI! BUGATTI! BUGATTI!



Steffen

P.S. the above is for Jean-Luc (Just search the Forum for his great start on this selfmade kit)

Mark: Great article!!!!!

I have a few questions (as I have tried some resin stuff myself)

1. My LEGO™ bricks do not fit that closely together (!?) .... the RTV leaking througth the joints like there were big holes ... do you seal the bricks?

2. I find your "sprue approach" interesting but also a little complicated. For Wheels and other simple stuff I only have seen one piece moulds. You do not have a seam line, you save expensive resin and the resin does not have to follow complex curves (with a good chance for air bubbles). Why did you choose this method?

BTW the resin I use is of a consistency like Revell /Faller glue maybe even a tad thicker (but cures in a few minutes) What do you use .. is it like water?

Thank you and

best wishes

Steffen

Let me try to address the issues:

Thae gates (risers) make it easier for the resin to fill the mold if you're not using a Pressure (or Vaccum) casting setup.

I have mior leakage with my Lego mold boxes as well. (run some tape around the in or outside to cover gaps)

The resin I use is alot thinner than others as well. the thinner it is the easer it is to pour and the better it fills the mold.

I Use a oral syringe to "inject" the resin slowly into the mold. (but I Don't use gates (risers) as of yet)

I use Smooth On Smooth cast 321 resin IDK if it's available on that side of the pond.

I have yet to make a 2 part mold as well. I usually just Slice the side of my mold then use a rubberband to hold it back together (a decent side wall thickness allows this)

HTH

Hi Matt

many thanks for the hints!! Hope i remember them until the next time I try the stuff myself ...

best wishes

Steffen

A good, very understandable article, Mark, nice job, and thanks for the effort, mate...as Jean-Luc has said, hope it's not the last!
Cheers,
~Gunny

Nice article Mark.

Very nice article, well done.
For lego leakage just tape or foil the inside and there isn't any.
I know with the RTV mold I use the length of your allignment rods would not last more than a few pours. I would opt for shorter rods - just a personal deal for me.

What is that Steffen?

Jean-Luc

Me thinks he is just trying to pester (bug) someone named Atti.

Mark, excellent article! Super subject! I hope you are archiving the building of the FC. Showing how to bring one of these old kits from 'also-ran manufacturers' to museum quality is a good way to inspire and encourage.

I, too, hope to see more from you.

Thanks for spending the time to put this article together. It is very helpful. I have always wanted to know how to do this and you walked through a succinct and clear process to do it. Thanks.

Marty

Folks
New to the site having trawled the web to find out how to make molds and cast items in resin. Came across Mark Bulcher's excellent article and am ready to try it out. However, there are a couple of questions that I need answered (Possibly silly questions to some!) but having not tried this casting lark before I wish not to make the mistakes that those before me have made and to get the best results that I can.

What is "RTV" abbreviated for in "RTV Silicone"?
What type of resin is used in Marks article to produce the quality of detail in his castings as there are numerous types of resins on the market?
(I note some of the other replies mention different types of resin but I am non the wiser at present).

Require three chimneys for a model building and, having crafted one, I do not have the will nor time to constuct two more. Casting seems to be the sensible approch to take to get all three looking the same.

Greetings, and welcome to Aeroscale!

RTV is short for Room Temperature Vulcanizing, people much smarter than I will have to answer the rest of your questions.

Steffen-

My apologies for not addressing your questions sooner. As a relatively new forum user, I had no idea there was a discussion group attached to an article. This site never ceases to amaze !

1. The Lego blocks fit fairly snugly, but there will indeed be areas that will leak slightly. That is why I wrap the outside of the Lego form with low-tack masking tape, and again at the bottom edges so nothing leaks out the bottom end.

2. The "sprue" method was utilized for two reasons: first, because there's less clean-up time on the wheel (less excess resin to remove from the wheel), and second, it is far easier to remove a cast part from a two-piece mold than from a one-piece mold, and as such, your mold will not tear from stress, like a one-pice mold can do. Another benefit is that you can cast several pieces at once if they're on a sprue, this is much more difficult with a one-piece mold. Try it, it's really not that complicated. You just have to be sure your parts are aligned on center with your pour spout and breather tubes, so your mold halves don't encompass any one attribute of the sprue.

The resin I use is available from MicroMark (www.micromark.com), it is their CR-600 High Performance Casting Resin. It has the pour consistency of water when fresh, and then to a light maple syrup about 4 - 5 minutes later.

Best regards-
Mark