Squadron green putty eating plastic?

[jmwallac]

Hello. I'm working on adding fender flares to the Revell '06 Mustang. I've added plastic card to create the openings and provide a "ledge" for the putty to hold to. The problem is, after 3 hours of drying, the putty still isn't dry. Whats worse is where the plastic card sticks out past the cars opening, the putty has "eaten" the card and made it very soft. It feels like the putty is still wet under the hardened shell. Does Squadron green putty typically eat plastic card? I also have 5 minute epoxy, but that stuff is a bitch to sand. Any ideas? Is the plastic ruined, or does it just have to "dry out" and reharden?

So much for my foray into scratch building. I can post pics if it will help.

[stevenoble]

I have the squadron white putty and if you apply it too thickly it can sometimes melt the plastic slightly.But you really have to put it on very thick to do damage.

[jmwallac]

Here are some pics if it helps.

[jmwallac]

Originally Posted by stevenoble

I have the squadron white putty and if you apply it too thickly it can sometimes melt the plastic slightly.But you really have to put it on very thick to do damage.

I'm guessing then that I applied it too thick? What now? Just wait for it to cure? Tear it off and start over? God I hope not....

[ZoomZoomMX-5]

It probably has some liquid styrene cement as part of it's chemical makeup to help it stick to plastic. You shouldn't apply this kind of putty in thick sections, as it takes a long time to dry and shrinks a lot over time. You are much better off using either epoxy putty (Tamiya/Milliput or ?), or an automotive 2-part polyester glazing putty like Evercoat Eurosoft or Metal Glaze as it dries rapidly from the catalyst and doesn't shrink over time.

To answer your question, you don't have to remove your putty but you will have to let it completely dry, and that could take weeks or months because it cures in the ambient air. So it's up to you; put this project on hold and let nature take it's course, or remove the putty and start over w/a better putty for the job. Most of the guys around here do bodykits like this w/Tamiya epoxy putty, it shapes nicely when "green" and sands pretty well when dry.

[CifeNet]

It's interesting that you are going through the similar work that I once did last year....

Unfortunately, I don't have any experience on the Squad. green putty, so I can't comment... But I think what does happen with the putty (generally speaking) is that, it has "thinner" type of liquid that actually evaporates as the putty hardens.

That thinner might have same acting substances as in the laquor thinner and it is possible that having the liquid affecting the platic itself. But, if the thinner dries out quickly (usually it does), I think you are okay. If it does't, I can see the problem that you are having can happen.

Either the putty is bad, or it needs a less humid place to have the putty dry quicker...

On the other hand, I would like to recommend you to use epoxy putty to do this kind of mod. I understand you didn't like to sand, but it does give you hard surface to shape your way~

Here are some pictures as to what I did and the result of using epoxy putty to have a wide body... I think you will see that epoxy putty is a good choice for this kind of mod... Good luck~

[energon]

Squadron green tends to be a bit "hot". You never want to put it on very thick. It also shrinks as was mentioned. Tamiya epoxy putties are definitely worth investing in. They are so much nicer to work with.

[jmwallac]

Originally Posted by CifeNet

It's interesting that you are going through the similar work that I once did last year....

Actually, since I saw your Mustang, I haven't been able to get this idea out of my head!!! Your car turned out great and I decided I had to have something similar. I doubt it will turn out looking that nice, but we'll take a run at it.

Originally Posted by CifeNet

Unfortunately, I don't have any experience on the Squad. green putty, so I can't comment... But I think what does happen with the putty (generally speaking) is that, it has "thinner" type of liquid that actually evaporates as the putty hardens.

That thinner might have same acting substances as in the laquor thinner and it is possible that having the liquid affecting the platic itself. But, if the thinner dries out quickly (usually it does), I think you are okay. If it does't, I can see the problem that you are having can happen.

As you and energon have pointed out, this green putty is pretty hot. As I'm extremely impatient, I ended up tearing the old styrene and putty off. It was still very liquidy at the bottom and the plastic was almost completely melted. Luckily the wheel arch was still nicely defined and the styrene cut away completely.

Originally Posted by CifeNet

On the other hand, I would like to recommend you to use epoxy putty to do this kind of mod. I understand you didn't like to sand, but it does give you hard surface to shape your way~

Here are some pictures as to what I did and the result of using epoxy putty to have a wide body... I think you will see that epoxy putty is a good choice for this kind of mod... Good luck~

Thank you for the in progress pics! I've switched to a 2 part 5 min epoxy as I don't have the Tamiya epoxy available. That helps to see how it was built up. Mine isn't that elaborate, but I think the results with the epoxy will be superior. What grit did you start sanding with? It seems as though the epoxy won't shrink like the putty did.

CifeNet, do you have any other in progress pictures? I'd like to see how the front chin spoiler and interior were handled. The stance of that car turned out great.

Thanks for all the comments and ideas. This site is great for quick and accurate answers!

[CifeNet]

Originally Posted by jmwallac

Thank you for the in progress pics! I've switched to a 2 part 5 min epoxy as I don't have the Tamiya epoxy available. That helps to see how it was built up. Mine isn't that elaborate, but I think the results with the epoxy will be superior. What grit did you start sanding with? It seems as though the epoxy won't shrink like the putty did.

CifeNet, do you have any other in progress pictures? I'd like to see how the front chin spoiler and interior were handled. The stance of that car turned out great.

Thanks for all the comments and ideas. This site is great for quick and accurate answers!

Thanks for your kind feedback. Just wanted to clarify, you are not using 5min 2 part epoxy "glue" as a putty, right? You would want to use epoxy "putty".

I have a various "files" (metal ones) which I used to shape up. Then I used 320 first, 400, then 1000.

I think I have about 120+ pictures of progress pic, but I never had a time to put together a WIP... I should share...

Let me quickly find some pics that you wanted to see below...

[jmwallac]

Originally Posted by CifeNet

Thanks for your kind feedback. Just wanted to clarify, you are not using 5min 2 part epoxy "glue" as a putty, right? You would want to use epoxy "putty".

I have a various "files" (metal ones) which I used to shape up. Then I used 320 first, 400, then 1000.

The product is called "quicksteel" and it is labeled as a plastic repair tool. You knead the two parts together and then shape it. It isn't a liquid type of epoxy.

Originally Posted by CifeNet

I think I have about 120+ pictures of progress pic, but I never had a time to put together a WIP... I should share...

Please do!!! Your models are very clean and turn out great. This one would make for an awesome WIP.

Originally Posted by CifeNet

Let me quickly find some pics that you wanted to see below...

Do you have any staight on shots? I'm trying to decide if I should integrate the lower grill or cut it out and have a large opening with mesh behind it.

Thanks in advance for any pictures/tips you can post.

[klutz_100]

Originally Posted by jmwallac

Please do!!! Your models are very clean and turn out great. This one would make for an awesome WIP.

I couldn't agree more!! Your work is outstanding and I definitely have a "hunger" to see more of it as often as possible

[hirofkd]

There're three kinds of putty commonly used by car modelers, solvent, epoxy and polyester.

Solvent putty, like Squadron's green putty, or Tamiya's gray Basic Putty are meant to eat styrene, so it blends with the surface. It's used to correct sink marks, and filling a small gap. The disadvantage is the putty shrinks as it dries.

Epoxy putty is like clay, and you can make your desired shape easily. It cures by chemical reaction, so it doesn't shrink, and suitable for thick application. The drawback is, generally speaking, it takes longer to cure (like 4-6 hours), and doesn't grab the surface very well. So when you use epoxy to make a body kit, roughen the area with a coarse sand paper, like 400-600 grit.

The last kind is polyester (which is my favorite), and it's also known as automotive body filler. This one also cures by chemical reaction, and the working time is 5-10 minutes. It's a soft paste, so it's a little messier than epoxy, but can be used for making body kits, too. The only thing I don't like is it smells really bad, but the putty is cheap and because the working time is so short, you can repeat applying the putty several times to form a thick object in a relatively short period of time. This putty also doesn't stick to plastic well, so the surface preparation is recommended.

[white_R34]

Hello to you all I've had that happon no some of my work. The putty I used was Testors Red putty you need to take in the info there telling you the Epoxy putty is the best but if you still don't want to sand for a long time just use you type of putty in thin layers you know build them up and then sand some say don't use the red putty or the white putty made by Testors; I still use them and my work comes out well. All-in-All it's up to you and your skill level. hope to see your work on AF soon. Thank you all for reading.

[jmwallac]

Thank you to everyone who had some advice. I tore off the old plastic card and putty (it was eating the plastic) and rebuilt the flares with epoxy. It's pretty rough now, but I'd like to start a WIP soon.

[Didymus]

Will Tamiya epoxy putty work for resin? What about Bondo? I have a big can of it that was intended for a (real) Porsche 914 that has now found a new home in Texas.

Didymus