Removing Glue From Models?

[John Clutch]

I don't imagine there is a chemical that removes dry glue from a model kit without damaging the plastics, but if there is, I would love to know about it. Thanks

Clutch

[BigTallDad]

What kind of glue? Solvent-based, CA, epoxy, etc.

[John Clutch]

Big, I'm not actually having an issue at the moment. I'm quite new to modeling and I thought I would ask this. I did search a few pages on the forum, but considering there are soooo much information, I thought I would start a thread. And then after starting the thread, I noticed the pinned post about how to search on this forum, which I didn't yet. I'm off today and I'm doing a bit of running around. But I guess my question was a general one to cover all types of adhesives.

[Jantrix]

A lot of us use a degreaser called Super Clean or Purple Power for stipping paint. Very often this will loosen glue joints, but aside from the debonder you can buy for CA Crazy Glues and the like, that's about it.

[JTalmage]

Some people will even dunk the car in water and toss it in the freezer. Ice wedging sometimes gets in the gaps and can help pop things apart. 

[Art Anderson]

  On 7/22/2015 at 1:34 PM, John Clutch said:

I don't imagine there is a chemical that removes dry glue from a model kit without damaging the plastics, but if there is, I would love to know about it. Thanks

Clutch

The vast majority of plastic model kits get assembled with plastic cement, formulated for this purpose.  Virtually all plastic cements made for use on polystyrene plastic (which is what most model car kits are molded in) work by actually dissolving the mating surfaces which allows the parts to "weld" together.  So-called "Tube Glues" (think Testors in the orange tube here) have a thickening agent in them (most often cellulose) to give them some "body" , keep them from just running all over the place.  

If your intent is to disassemble a built model with minimal damage, the old trick of placing the model in a plastic bag, then putting water into that bag, finally putting it in the freezer does work--water as it freezes, expands in all directions--which can force the parts apart.  However, if what you are wanting to do is to remove the glue "residue" from the surfaces of polystyrene plastic model parts--anything that will dissolve the dried tube glue will also dissolve the plastic underneath or surrounding it.  Consequently, about the only way to "remove" those residues is with files and sandpaper--which can be done (I've done it several times over the years), takes time, and will require painting to hide the inevitable marks that remain.

 

Art

[John Clutch]

Gentlemen, thank you for your responses. I was aware that some glues actually melt/weld the plastic components, but being new to this after 30 years, I thought maybe some new technology has come to light since then. But then again, why fix something that isn't broken, right? I like that freezer trick and hope so day I get a chance to try that. 

[Snake45]

Yeah, glue joints most often have to be broken or cut apart, and random "glue boogers" removed by cutting, filing, and/or sanding. All part of the fun.

[Perspect Scale Modelworks]

I found a built kit online that was pretty much a glue bomb. The part that bugged me the most was the poseable steering was glued with one front wheel higher than the other. I thought about the freezer trick which I've had mixed results with in the past. Then I thought about something I had in the garage called Freeze-Off made by CRC. Works great on rusted on bolts by what the can says is a "freeze shock action... immediately drops the temperature of the area in direct contact". The nozzle comes with a small straw to direct the spray in tight areas so I gave the pieces a quick shot and it worked. Parts separated without breaking or damaging the plastic. This is nasty stuff so if you try it do so in a well ventilated area or outside and use a mask and goggles and all those safety measures.  I washed the parts in dish soap and water and was good to go. This was the first time I tried it so I'm not saying I swear by it but I will try it on the next glue bomb I come across. Individual results may vary. 

 

Edited August 31, 2015 by Perspective Customs

[Ace-Garageguy]

That's a new one on me. Gotta try it. Thanks.

[Harry Joy]

Just to add to the general knowledge, everything said above about liquid cements and tube glues is correct - you are looking at trying to separate welded parts. However, if you are using CA glues, and many do for some applications, it is easier to separate parts. CA is essentially just a butt join, not a weld, and many parts can be separated with a quick, sharp smack. CA glues have poor shear strength. Residue can be sanded off. A stubborn CA join can be hit with a CA debonder (most of which involve acetone, in case you are allergic).

I use Tamiya Extra-Thin Cement and CA on all of my builds, and which one I use depends on the particular application. I tend to use liquid cement for body work, or to add extra strength to structural parts. I use CA for most everything else - engines, interiors, small parts, essentially detail stuff where shear strength is not an issue. It is not unusual for one of my models to have exclusively liquid cement on all exterior visible parts, and CA on all interior parts.

Edited September 2, 2015 by Harry Joy

[Russell C]

  On 8/31/2015 at 3:41 AM, Perspective Customs said:

.......Freeze-Off made by CRC. Works great on rusted on bolts by what the can says is a "freeze shock action... immediately drops the temperature of the area in direct contact". ....

http://www.autozone.com/greases-and-gear-oil/lubricant-grease/crc-freeze-off-super-penetrant/898352_0_0/

[charlie8575]

I've had a couple of people suggest applying a very small amount of mineral spirits to the parts, disassemble and quickly wash as a possible way to fix the problem. 

I'm going to give it a try on a couple of parts and see what happens. I would venture you don't want it sitting on the plastic too long, maybe a few seconds to a minute; essentially enough to soften the joints, disassemble and rinse clean ASAP.

Charlie Larkin