Plastic filling/welding.

[Coops]

Ok, almost every manufacture has sink holes in thick plastic parts. Basically it’s the result of cooling/contracting (thermal contraction) of the plastic in a large volume part.
AFV and Trumpeter appear to struggle more often than Tamiya or DML and, disappointingly, most often around the breach area of the gun which is an extremely visible part (always shinny and attracting the eye to any blemishes).
The advantage of this way is that the plastic “filling” is exactly as hard as the part you’re fixing making it no harder to clean up than any other part of the kit. You can use this to fill anything you want, sink holes, gaps, joints, ejector pin holes or anything that needs filling or building up in plastic. I also suspect that stretched part tree could be used to “weld” PE to the plastic.

So the first pic has all you need to fill the hole and build up the surrounding area without using the extra effort of putty (working with plastic is something we all get good at, no?).

1: make the hole a bit bigger with the tip of your number 11 blade.

2: fill the hole with thin plastic cement (your choice but one that softens is critical) and the tip of the bit of tree which you carve roughly to shape.

3: after you wait 5 min, refill the hole to flush with glue and press the bit of the parts tree into it. You are looking to see glue and melted plastic ooze out from around the joint.

4: wait for it all to dry, it’s critical that you wait for the plastic to re-harden so you can sand it back flush.

I hope that this ridiculously cheep use of scrap plastic helps out.

Coops

http://i250.photobucket.com/albums/gg250/SteveCoops/TnT001.jpg

http://i250.photobucket.com/albums/gg250/SteveCoops/TnT003.jpg

http://i250.photobucket.com/albums/gg250/SteveCoops/TnT002.jpg

http://i250.photobucket.com/albums/gg250/SteveCoops/TnT004.jpg

[greybeard]

I use 'goop' too. Start with a new jar of liquid cement (the cheap stuff) and drop chunks of sprue into it. Wait 24 hours and check the consistency. It should be 'goopy' but not "string" when you stick a toothpick into it.

Too much plastic is bad — several thin coats work best. Don't use white styrene, as it has too much filler and won't mix well.

Using it requires much patience. Thin coats dry faster and harder and don't shrink as much. It does shrink, so sometimnes you need to apply a second coat. If you glom too much on, it can take two or three days to harden to where you can sand it.

If you mess up, and get some where you don't want it, let it dry and then remove it with a sharp blade. Trying to remove it when it's wet can end up damaging the underlying plastic.

It can also be used as cement. Put a drop on a piece of glass, use an old paintbrush to add more liquid cement, mix well and apply with a toothpick. It's a good gap-filler.

Cheers
Scott Fraser

[Panzergrenadier]

A top tip to remember, must give it a try.:cool::thumb:

[Coops]

I use 'goop' too.

G'day Scott, thanks for your input, I like Tamiya filler that I cut back with glue (put a dollop on a bit of plastic and add glue, then mix it up to suite) :).

The idea behind the bit off old tree is that you only have to clean up the bit you glued on and there is NO shrink.
If you cut slots in the end of the tree it softens very fast and the plug dries very fast.
The bit above took about 6hr to dry.
Coops

[greybeard]

G'day, eh?

. . . I like Tamiya filler that I cut back with glue (put a dollop on a bit of plastic and add glue, then mix it up to suite) :).
Coops

I prefer to use "automotive spot body putty" commonly called "blue stuff". It is soluable with the same things that glue plastic, dries hard, quickly, and is easy to sand and carve. It does shrink a bit, but a 16oz tube cost $3 back when I last bought one, and if you keep it sealed you have a lifetime supply.

Cheers
Scott

[Coops]

I'll give that a try Scott, sounds very cheap and effective (always a good thing to a husband/fathers ears:)).
Coops

[greybeard]

LOL! I learned a long time ago to seek alternate products, ever since I saw an ad for "Squander Shop Decal Activating Solution". $5 for three ounces. "Slip your decals into it and after twenty seconds they slide right off the paper!"

Cheers

[James Tainton]

These are a couple of the items I use for filling. The two part expoxy putty is great, hardens fast and is sandable in ten minutes or so.
The Red glazing putty is also useful. The plastic is good but the time factor is a minus to an impatient guy like me. There are other things I use as well Like Mr. 500 .
http://panzerfaust.sslpowered.com/General/putty.jpg

[Flak]

Thanks for sharing... :)

[Jan Peters]

A quicker way to fill holes is to melt the sprue with a lighterflame, and push it into the hole. The plastic will fill the hole, and after you put some Tamiya ET (or the like) on it it will be workable after drying. I use it to plug big holes (in the hull for instance) It works best when you do it from the inside, and take care with thin parts, as the heated plastic can warp your part.
Jan :)

[Sturmmann]

Interesting idea Steve.

Im going to have to try it out.

Dave