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Resin body slowly dying!!

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1 hour ago, Bucky said:

I know this thread is about resin, but I kinda wonder if 3D printed parts might do something similar.

Good question!

With the hobby heading in this direction, it would be very beneficial to know that.

 

 

 

Steve

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3D print!! Yes very good question? I am curious if other resin or 3D printed piece(s) may perhaps dry out or react in time to certain paints? (my 55 sedan delivery sure did) or,... am I/we getting paranoid about certain materials used? The resin from the 55 delivery might not have been the exact "formula" when casted and may be the only resin cast that went down the,.....!!! So buyer beware?!! I have since built another resin cast from a different supplier so,..... we will see in time? 

3D is very cool stuff and I hope it out lasts all the above!!

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The materials "resin" model car parts are made from belong to the thermoset plastic family, related to but different from epoxies and polyester.

https://en.wikipedia.org/wiki/Thermosetting_polymer

Good quality resin parts are very stable over time.

Poor quality parts made from old material, extremely cheap material, or sloppily mixed with little regard for exact mix-ratios (very common among some cowboys who think it doesn't matter) will exhibit shrinkage, warpage, and embrittlement over time.

This is why we have to keep record samples of every thermoset plastic mix used on a structural aircraft repair, and usually send samples for testing by an independent lab prior to the aircraft being returned to service.

I have a few bodies that are warping, but not as severely as yours. They've never been painted, but were just made with crapp, or poorly. The most recent one that came in is an early Falcon sedan delivery, as swaybacked as an old horse.

My SOP these days, when I get a resin body that's something really unusual that I really want, is to immediately pull silicone  molds from it to preserve the 3D information in the event something like this happens.

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I'm wondering if this could be the type of paint. Was it a lacquer that could be attacking it? It will be interesting to see how resin will react to acrylic paints.

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1 minute ago, iBorg said:

I'm wondering if this could be the type of paint. Was it a lacquer that could be attacking it? It will be interesting to see how resin will react to acrylic paints.

Properly mixed thermoset parts made from decent materials are generally very highly solvent resistant.

And with lacquer paints, which dry by solvent evaporation, all the solvents that could have affected the resin should have been gone years ago.

But without knowing exactly what this poor thing was made from by doing a chemical analysis, anything is pure speculation.

However...in 5 decades of working with thermosetting plastics, and seeing the problems some folks have, the single most common failure point I've encountered...by a LARGE percentage...is operator error of some sort on the part of the resin user.

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I really hope my resin bodied 1/12 Model Factory Hiro kits don't exhibit this behaviour in years to come.

It's well documented that some die cast models suffer from what's referred to as ' die cast cancer  ' as they have aged.

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Resin is a mixed compound, there are many types where their chemical make-up differs, so I would guess it depends on what manufacturers resin mix was used by the maker. Also, the mix has to be dead right, otherwise something that looks as though it is set could still be de gaussing for a considerable time after manufacture. Maybe there is a pattern as to what individual cottage industry manufacturer's products are more prone to this problem due to the actual resin they are using. Unfortunately at the time of casting they would be completely unaware of any inherent latent problems with the material they were using manifesting itself at a later date.

Makes you wonder about the stability of materials that are being used for 3D printing as well in the long term?

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I would expect 3d printed stuff to warp pretty quick with the heating and cooling during the print process so we'd see it faster (speculation on my part, no experience)

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4 hours ago, stitchdup said:

I would expect 3d printed stuff to warp pretty quick with the heating and cooling during the print process so we'd see it faster (speculation on my part, no experience)

There are different types of 3D printers. Sounds like you are talking about the ones which use hot filament. But then there are printers which use liquid UV-light-curable resin. No heat.

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17 hours ago, Ace-Garageguy said:

 

Good quality resin parts are very stable over time.

Poor quality parts made from old material, extremely cheap material, or sloppily mixed with little regard for exact mix-ratios (very common among some cowboys who think it doesn't matter) will exhibit shrinkage, warpage, and embrittlement over time.

 

Yup.

 

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It’s interesting how some resin will behave itself and some will shrink, and you never know if your parts will fall victim until it’s too late. I have several built full resin airplane kits that are at least 20 years old and they are still stable. I have another that’s probably 15 years old and one fuselage half has shrunk so it’s almost 1/4” shorter than the other! They fit together perfectly when I bought the kit.
 

Ben

Edited by Ben Brown

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I have an unbuilt Perry's Resin S-10 and the rear frame rails are starting to bend upward. I think I can probably straighten them with hot water when I get around to building the kit. I will use epoxy to install the bed as well. Rest of the parts still look OK.

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That will be a temporary remedy. Go back to what Bill said about resin quality. That frame will exhibit warping and deformation in other locations in the future.

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I am really appreciating the response to the "dying resin" ,..... guess it comes down to quality or not! I think its trial and error on the castors part? But the "formula" will keep you in business? but how do you know as time ticks away that the product you produce is solid?

 

thanks for everyones sympathy and response

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I pulled a model off my shelf to take some photos recently, and discovered that one of the whitewall tire inserts that I'd cast in white resin about 9-10 years ago had shrunk badly. I only noticed when I saw that it had pulled the tire partially off the wheel! Clearly I didn't mix the resin properly...but it took many years for the failure to become apparent.

Bummer about the '55 Lorne....and I agree about wanting to know if 3D printed parts will have similar issues. So far so good, for me, but I only have printed parts going back about 3 years.

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Thanks Spex84!

your right it is a bummer!! The 55 was my first contest table "contestant" !!  It did well back then,...now its time the 55 retires. Good from far, but far from good,... that's time.

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On 1/16/2020 at 12:00 AM, Roncla said:

I really hope my resin bodied 1/12 Model Factory Hiro kits don't exhibit this behaviour in years to come.

It's well documented that some die cast models suffer from what's referred to as ' die cast cancer  ' as they have aged.

I hear ya on that! I have some reaalll expensive 1/12 and 1/24 Model Factory Hiro kits and I sure hope to heck they don't go bad. I would be rather ticked when the fancy strikes me to build one of them and then much to my surprise and chagrin, they've turned into an unbuildable mess. :(

I thought some years ago there were some Danbury and Franklin Mint models that seemed to suffer from "diecast cancer" as they got old. I may be thinking of something else, but I thought that was a thread here once. 🤔

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13 hours ago, MrObsessive said:

I hear ya on that! I have some reaalll expensive 1/12 and 1/24 Model Factory Hiro kits and I sure hope to heck they don't go bad. I would be rather ticked when the fancy strikes me to build one of them and then much to my surprise and chagrin, they've turned into an unbuildable mess. :(

I thought some years ago there were some Danbury and Franklin Mint models that seemed to suffer from "diecast cancer" as they got old. I may be thinking of something else, but I thought that was a thread here once. 🤔

Diecast cancer is an issue that has afflicted many different brands over the years. I had some Revival metal  kits here in the past  and their pre painted bodies started to bubble,

Thinking it was the factory paint I stripped them  only to find it was the metal  that was bubbling beneath the paint. 

I sanded some parts smooth and resprayed them but within a few years the metal was bubbling again.

Getting back to resin issues I have several sets of C1 Models resin wheel  & Tire sets I purchased a few years ago which are no longer fitting together.

IMG_3320.jpeg

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14 hours ago, MrObsessive said:

 

I thought some years ago there were some Danbury and Franklin Mint models that seemed to suffer from "diecast cancer" as they got old. I may be thinking of something else, but I thought that was a thread here once. 🤔

This is true.  Apparently some of the "alloys" used to make the diecast parts were mixtures of metals that don't like to be mixed with one another.

I have seen several 1/18 scale cars that suffer from this also: big chunks of paint coming off, parts "swelling up", parts crumbling.  Some early Hot Wheels cars are afflicted with this also; from what I have read, there are a couple of HW cars that are difficult to find in any condition.

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18 hours ago, MrObsessive said:

I hear ya on that! I have some reaalll expensive 1/12 and 1/24 Model Factory Hiro kits and I sure hope to heck they don't go bad. I would be rather ticked when the fancy strikes me to build one of them and then much to my surprise and chagrin, they've turned into an unbuildable mess. :(

I thought some years ago there were some Danbury and Franklin Mint models that seemed to suffer from "diecast cancer" as they got old. I may be thinking of something else, but I thought that was a thread here once. 🤔

While a totally different material (metal) and a different problem, the end result is defective model. It is called "zinc rot" or "zinc pest".

https://en.wikipedia.org/wiki/Zinc_pest

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I am sorry that such a nice model is decaying for you. I never really bought resin, because I feared this type of thing. Also, I just didn't like working with it, compared to kit plastic.  I have had a BIG issue with diecast paint rash and "cancer." I had a lot of 1/18 diecasts and have sold most of them because of this. I don't buy them anymore, even though there are some really nice models out there. I do have plastic kits that go back to the late 50's/early 60's and they are still in excellent shape. I know there are the tire issues people talk about, especially Revell tires damaging or melting original wheels.I have not had too much trouble with this. The only other issue is decals, but I have always expected them to deteriorate because they are paper.

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Once 3D printing materials are proved to be stable, the great thing is that being made from a CAD program instead of a mould with a limited shelf life, the repeatability is endless, from one off parts to batches. The UV setting process that Pete mentioned in one of his posts appears to be most stable. My dentist repaired a chipped tooth two years ago using a UV setting compound that is still good today.

Edited by Bugatti Fan

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Stability of 3d printed items overall is much more serious than parts placed on model cars.  There are critical applications such as printing replacement parts for machinery and implanting parts in human bodies.   

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Hey Roncla

Thanks for posting the photo's on the die cast VW and the wheel set!!! Wow their shelf life didn't last either? That has proven to me that the "stability" of materials is a hit and miss?! I finished my second resin body with full detail and unlimited after market parts ( Im a detail freak) So I will cross my fingers that it survives!!

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On 1/15/2020 at 6:30 PM, Bucky said:

I know this thread is about resin, but I kinda wonder if 3D printed parts might do something similar.

There's no blanket answer, though there seems to be an implication in this thread that there should be.

Plastic 3D parts are made from a variety of different plastics, using different processes.

Filament-printed parts are made from thermoplastics like polystyrene and ABS, and will exhibit the same longevity and stability characteristics as the base plastics the filament spool is made from. Just as model car "styrene" can vary in quality from manufacturer to manufacturer, so can printing filament.

3D printed parts made from liquid resin are essentially modified thermoset plastics, with some characteristics in common with traditional "resin" parts...but light, typically UV, is used to initiate and complete the cross-polymerization that makes the goo hard. With traditional "resin" parts, the polymerization depends on the addition of a chemical "hardener" or catalyst, and sloppy measuring can have a dramatic effect on part performance over time.

The light-curing liquid resins don't depend on idiots adding carefully measured chemicals to make them work. The chemical engineering that's done by the resin supplier should be a reasonable guarantee of uniformity and stability, but you really can't depend on that 100%.

Light-curing resins in 3D printing applications may also depend on "post-cure" procedures, like a lengthy bath in UV light, to fully harden them after printing.

If this isn't done, or isn't done correctly, you're going to have instability and deterioration with these as well.

 

 

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