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Old FFForums Archive => Model Help* (Check Stickies and Search First) => Assembly/Scratchbuilding => Topic started by: louis on April 03, 2009, 07:10:49 PM

Title: Puttying disaster!
Post by: louis on April 03, 2009, 07:10:49 PM
Yesterday I bought a Tamiya Putty (basic type) the I applied a few amount inside the chest area trying to bond together the connector part to it, then I left it overnight, while I was checking it this morning the chest part melted a little but its visible, the melted part looks like its "chewy". What will I do to remove the melted part?
Title: Re: Puttying disaster!
Post by: FichtenFoo on April 03, 2009, 08:04:38 PM
Were you using a lot of it? I've never had that happen. But I've only used it to fill small gaps and seams, not as a glue.

As for removing the melted part, depends on whether you want to "save" it or rip it out.
Title: Re: Puttying disaster!
Post by: Zircor on April 03, 2009, 08:12:02 PM
Yesterday I bought a Tamiya Putty (basic type) the I applied a few amount inside the chest area trying to bond together the connector part to it, then I left it overnight, while I was checking it this morning the chest part melted a little but its visible, the melted part looks like its "chewy". What will I do to remove the melted part?


I've had the same thing happen with Squadron Green, and only when applying a LOT to try and fill in a large open area (such as filling in half of an open weapon ala some of the SD kits, and in my case 1/144 Gundam X kit).  There's a chemical in the putty that will react with the plastic to bond to it, but in large quantities will weaken it.  For that type of application I later learned that 2-part epoxy putty will work good instead.  Tamiya basic and squadron green are for small scratch filling and stuff like that.
Title: Re: Puttying disaster!
Post by: Red Comet on April 03, 2009, 10:16:18 PM
I've had this problem when I first began in the hobby.

As mentioned above, too much of this putty will cause the plastic to soften and become 'like chewy'. This stuff is only recommended for small gaps and seams not for an adhesive. Use CA glue first to fix the parts together and fix the seams using the putty.

As Zircor says, for filling larger areas use epoxy putty. Milliput is my brand of choice in this range.
Title: Re: Puttying disaster!
Post by: Zircor on April 03, 2009, 11:39:24 PM
Use CA glue first to fix the parts together and fix the seams using the putty.

Or something like Tamiya Extra Thin cement will do the same.  Just depends on your preference  :)
Title: Re: Puttying disaster!
Post by: fulcy on April 04, 2009, 03:07:21 AM
These types of putties typically contain a chemical solvent called toluene (known to the state of California to cause cancer - so if you live outside of California, you're ok), which is used to 'cure' the putty.  These putties cure basically because the toluene evaporates.  However, if you use the putty in large amounts, the toluene is concentrated enough and not able to evaporate because of the sheer mass of the putty.  Since toluene is a solvent, when it is left in contact with plastic for a long enough time in high enough concentrations, the plastic melts.  This is also why these types of putties tend to bond to styrenes a little better than other putties - the toluene, before it evaporates, melts the surface layer of plastic, giving the putty something to bite onto as it dries.
Title: Re: Puttying disaster!
Post by: louis on April 04, 2009, 05:54:00 AM
I'm new in trying to modify a gundam kit, I've panicked a little and removed the all the putty, but now the chest part has a huge hole on it, can I use ordinary household epoxy and sculpt and use it to close the gaping holes on it?

In my country its difficult to search a modelling shop to buy tools and materials, so can I know what ordinary items I can used that wont melt my plastic kits.
Title: Re: Puttying disaster!
Post by: clee-cm on April 04, 2009, 08:52:14 AM
Sorry to hear about your model.   ???  :(

If you can't get Milliput putty (I prefer silver-grey putty); you can give Tamiya Epoxy Putty a try, I have never used it before. Many of the major Japanese model paint manufacturers also make modeling epoxy putty, but when you get right down to it, you can use any type of A+B Epoxy putty as filler.

Usual A+B epoxy putty is sold as plummer's putty at the hardware store.
Title: Re: Puttying disaster!
Post by: Bawoo on April 04, 2009, 11:22:38 AM
I try to use hardware store or commonly available products as much as I can, partly because I'm cheap and stubborn, and partly because I live in a small town.  There's lots of good stuff out there!

I do use hardware store plumbers epoxy putty a lot, but make sure to test whatever you buy before putting it on your model!  There are a lot of varieties sold at hardware stores, and they're not all suitable for modeling.  Some cure sort of rubbery, others cure VERY hard and are impossible to work after curing without power tools.  The kind I use is dark blue with white center.  I've tried various brands, and the ones with this coloring all seem to be the same.  I actually like it better than "modeling" epoxies for most applications.  I have tried some that was grey (cures slow and hard), light blue (rubbery), copper colored (rediculously hard), and silver (hard).  The dark blue is the only one I can use for modeling.  I'm not sure if the same will be true for what you find wherever you are.

Another great filler (hard to know what you need without seeing a pic) is superglue mixed with corn starch.  Just mix it on a piece of wax paper or an old yogurt container lid, in approximately equal parts (the ratio depends a little on what you're doing and the viscosity of the glue you use).  It cures up pretty hard and fast, but sands and carves well.  If you're trying to back-fill a part that was eaten by the Tamiya putty, this might be a good choice.  Once again, play with some tests before you put it on your important project.

Or there's polyester putties, 2 part autobody fillers at a hardware or auto parts store (Bondo here in the states).  This stuff cures a little softer than the above options. 

If you post a pic of the damage I can be more specific about suggested fixes...
Title: Re: Puttying disaster!
Post by: louis on April 04, 2009, 03:44:48 PM
This is the chest areas that's gotten chewed up, I've kind of carved it off and make it square shape.

(http://i118.photobucket.com/albums/o96/kaiser013/Image066.jpg)

(http://i118.photobucket.com/albums/o96/kaiser013/Image0601.jpg)
Title: Re: Puttying disaster!
Post by: FichtenFoo on April 04, 2009, 04:41:23 PM
What kit is that? Looks familiar, but I can't place it.
Title: Re: Puttying disaster!
Post by: louis on April 04, 2009, 04:50:19 PM
It's a Gundam Deathscythe Hell Custom 1/100 HG. I was modifying it to have a torso joint and articulations for its shoulder. I was trying to replicate Whitebase modification in his 1/144 scale Gundam D-Hell as posted below.

(http://i118.photobucket.com/albums/o96/kaiser013/DSHC_WIP_Pose013.jpg)
Title: Re: Puttying disaster!
Post by: Bawoo on April 04, 2009, 05:52:06 PM
So the holes in the top of the chest piece are the problem?  Pretty easy fix - cut some plastic sheet to approximate size to fill the hole, glue in place with CA (superglue).  You can buy garage sale or simlar signs if you can't find "hobby" plastic sheet.  Glue some thin slices around the edges from behind for support.  Then use the filler of your choice to smooth things out.  In this case I'd probably go with superglue/corn starch mixture, but with your limited experience the Tamiya putty is going to be easier to sand and smooth out.

Another alternative if you have plastic sheet that's thin enough, is to cover the entire upper surface with a piece cut to shape (one for each side).  This woud be easier to get a smooth surface.  You can probably trace the shape on paper and transfer to the plastic.
Title: Re: Puttying disaster!
Post by: louis on April 05, 2009, 01:52:48 AM
Thanks for the tips now I was able to slightly repair the damage made to the kit.