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Unbuilding a kit
Washington, United States
Joined: November 05, 2005
KitMaker: 4,950 posts
AeroScale: 3,192 posts
Posted: Monday, November 12, 2018 - 07:05 PM UTC
I've recently scored a couple of 'used' kit lately. In most cases they're poorly assembled with tube glue. Excess glue in places, total lack of glue along parts of seams. Anyone have any good hints for unbuilding the kits so I can start them over and even get the interiors painted?
Berlin, Germany
Joined: October 12, 2008
KitMaker: 709 posts
AeroScale: 651 posts
Posted: Tuesday, November 13, 2018 - 12:48 AM UTC

Hi Mark!
Really? I think there's nothing like a "de-glue"-something.
As for me, sanding and repainting (even the interior parts in place) seems to be the only solution. Otherwise you will seriously damageing the glued joints when try to separate them with force.
Just my 2 cents...

Th mas
Staff MemberAssociate Editor
Rhode Island, United States
Joined: March 05, 2014
KitMaker: 2,888 posts
AeroScale: 307 posts
Posted: Tuesday, November 13, 2018 - 12:54 AM UTC
That's the thing about styrene glue; it's supposed to fuse the plastic so I would think generally there's no going back. Some of the old, cheap glues didn't do such a good job of that, so maybe you might get lucky with just prying them apart.

Good luck!

New Mexico, United States
Joined: June 16, 2014
KitMaker: 681 posts
AeroScale: 14 posts
Posted: Tuesday, November 13, 2018 - 01:18 AM UTC
If the joints are not really tight, a razor saw can be used to separate items sort of like removing resin parts from their mold blocks. Any damage done can be repaired with sheet styrene or rod. Iíd only do this for something thatís extremely rare or super expensive since it will 3 to 5 times the work to get a good result.

Paul H
Christchurch, New Zealand
Joined: February 01, 2006
KitMaker: 1,673 posts
AeroScale: 1,517 posts
Posted: Tuesday, November 13, 2018 - 09:55 AM UTC
I've used mineral turpentine to soften the joints and then slowly run a scalpel down the join. Care needs to be used as it will soften the plastic to if it's applied to liberally. Tube glue uses a resin component that's susceptible to mineral turps and it softens it to the point of being able to literally slice them apart. It will however also cut through any locating lugs or pins so you'll need to replace them with something else.
Washington, United States
Joined: March 15, 2009
KitMaker: 3,670 posts
AeroScale: 833 posts
Posted: Tuesday, November 13, 2018 - 10:34 AM UTC
Usually, depending on the joint, cutting, puttying and sanding are the only ways to get things apart. However there are two other methods I've used are Freezing and Oven Cleaner mixed with Ammonia (the least desirable for lots of reasons).
1.) I've actually been able to separate parts from glued up kits, including whole fuselages of aircraft and car bodies by soaking them in water for a couple of days (to insure water penetrates any gaps), placing them into a plastic bag, and immediately popping them into the freezer. This process de-laminates joints by allowing water to penetrates the joint gaps and expanding slowly, forcing the gap open. You may still need to do some repair work later. It doesn't always work, depending on the strength of the glue and type of glue, but it has worked for me in the past. Keeping the model loosely in a plastic bag ensures all the parts stay in one location and don't "ping" off into the freezer (don't ask me how I know).
2.) By soaking the model in Oven Cleaner mixed with a half cup of Household Ammonia for 24-48 hours (most oven cleaners use Ammonia as an active ingredient), you can sometimes weaken some glues to a point where the joint will deteriorate. Unfortunately, some plastics also become brittle during the wait, and both Ammonia and Oven Cleaner are smelly and require safety precautions (like gloves and eye protection, and a face mask).
Other solutions such as using acetone or further "un-gluing" with additional liquid cement usually just result in a breakdown and "melting" of the surrounding plastic. Hope this helps.
VR, Russ