Resin Casting

[FEC Railway]

Does anyone here have the ability to or know a source of someone that will do resin casting of a shell?  I need about 10 copies of a short hood with lowered headlight i've made.

Please Advise.

[VonRyan]

There are a couple folks here who have the capacity, but whether or not they have the time is anyone's guess.
If I had my workshop set up and materials on hand, I'd consider giving it a shot, but I need to focus on getting regular product out onto the market before I take on commission jobs.

[jpwisc]

The eBay vendor "bigdawgoriginals" would do them for you, he uses a good resin and knows how to cast pretty well.

[mcjaco]

Bill Denton at Skytop Models might be worth asking.

[JMaurer1]

If I had some fresher supplies, I would do it for you. The shipping cost of ordering the supplies have just become so extreme, I haven't ordered any new stuff for awhile and no longer would trust the stuff I have (over a year old). There's some other guys who cast here, maybe they will chime in...

[randgust]

I'll certainly look at it.    I'm making resin kit parts nearly every day this time of year.   Part of the plan is whether or not the part can continue to be publicly sold beyond your own needs, and that's also depending on if the master is original work or not.

See the randgust.com web page for the direct email.   

[Angus Shops]

I've done quite a lot of resin casting and would encourage any modeller to learn the basics. It's a really useful technique and really very easy to master the basics. Any model item you need more than one of is a suitable candidate for resin casting. Even if you don't need more than one, chances are your buddy can use one.

The biggest challenge I had was finding a steady supply of reliable, easy to use products. I've settled on Smooth On  products (Mold Max 30 for the mold material, and Smooth Cast 300 for the resin). Total investment for the smallest quantities of each (would make about 1000 short hoods) is about $65.00 retail in Vancouver.

You also don't really need any pricey equipment such a vacuum chamber (I don't); I don't have much of a bubble problem. Most bubbles are easily filled with a drop of resin, or you just make new part.

I started out with a relatively simple part and moved on to progressively more complex projects to the point that the idea of tackling a complete heavyweight passenger car is not daunting at all. Making your own parts will also save you a pile of cash in the long run.

You could make the mold of your part in 24 hours, and cast all 10 copies the next day.

On the other hand, I would be happy to help out, if you want...

Geoff

[JMaurer1]

I use mostly Smooth-On products myself...problem is there isn't a retailer nearby. I used to order from them and have it shipped to me but last time I checked the shipping was sky high as so much of the stuff is flammable or hazardous. Just checked and it's better than it was...starter casting kit is $52 (miss the old specials where the kit was $30) and shipping still seems a little high at $20.

[glakedylan]

NOT trying to hijack this thread
BUT I have a question...
I received two resin cast boiler shells for a steam locomotive
each shell has gaps in it
is there a remedy other than putty?

[pnolan48]

I find it very hard to mold and cast any complex surface less than 0.030" (0.75mm) thick. I suggest you use a longer setting casting formulation (eg. SmoothCast 310 rather than 300) to allow air to escape and resin to flow, along with lots of vibration. The 310 formulation has a setting time of about 4 hours rather than 10 minutes, which makes production of multiple copies a much lengthier process.

If you've got a casting with big holes, I'd ask the supplier for a replacement. I just throw away anything with more than a few tiny air bubbles. Even Bondo doesn't stick well when used to fill big holes in thin material.

I build my own masters, so I have control over things like release angles, air escapes, and clearances. If you are trying to duplicate something already built, especially from injection molding, you may have to build a two- or four-part mold, essentially duplicating the original mold.

I cast items only if they are (1) very hard to build but also castable, or (2) I need more than 5 copies. If I can build 5 copies in the time it takes me to make a mold and cast the first items, then it's a toss up. I cast and mold most small boats and fittings; I build linear parts like hatch coamings or freight car sides from cut styrene.

[VonRyan]

NOT trying to hijack this thread
BUT I have a question...
I received two resin cast boiler shells for a steam locomotive
each shell has gaps in it as if the casting was not done well
--do not want to name names, so let's just keep it to the information provided above--
NOW the question:
is there a remedy other than a load of putty?
can the current shells serve as a master for casting new ones that would be complete and not with gaping holes?
I put some good money into this purchase and would like to see something useable come out of it.
OK...back to OP purpose of this thread with hopefully a few answers to my questions thrown in.
sincerely--

Unless you can fill it with the same resin that was used in the casting, your only option is to fill the gaps with a filler/putty.
If the castings are 1st-Generation (meaning they are directly from a mold that was made with the original master), then they can potentially be used as masters for making new castings, but it would need to have the gaps filled in anyway. Those subsequent castings would then be 2nd-Generation and with something as detailed as a steam locomotive boiler, that would be as far as I myself would be willing to go. After that the detail quality will diminish with any further generations.

My personal philosophy is to try and sell only 1st-Generation castings, or 2nd-Generation at the very least.
With today's 3D printing technology, it is better to just print another master rather than sacrifice the quality of the castings.
This philosophy extends to the point of being my company policy.

[pnolan48]

I think, from experience, that even filling in the gaps with the same resin formulation will not work well. The new resin may not stick well to the old resin, even if exactly the same formulation.

[glakedylan]

the squadron putty route has not gone well

I will try the other methods noted here
I appreciate the information
thanks!

[nscaleSPF2]

the squadron putty route has note gone well
the surfaces with gapping holes are rounded in more than one direction

Gary,
Here is something that you may want to try.

Mix a small batch of epoxy (1 hour setup time).  Use the surface tension of the glue to spread it across the gap and let harden for 24 hours.  Use the putty to fill in the resulting depression.  If the gap is too big for this, you could use a tiny piece of paper to back up the glue.

This worked for me.  (Yes, I also bought a couple of resin shells that had this issue).  Remember that issues are to be overcome.

[pnolan48]

My absolutely last ditch recovery technique is similar. Glue a piece of white bond paper to the inside with white glue or similar. Fill the hole with white glue and let it set. Refill the hole if needed. Carefully sand the white glue plug to shape. I actually use "canopy glue" which is a fancy white glue for building up windows. Krystal Klear is a model railroad brand; I get it much cheaper from the model airplane folks. It sticks pretty well to most anything.

Oh yeah, clean the casting very well as a first step.