The gap won't fill!!

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RedHeadKevin
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The gap won't fill!!

Post by RedHeadKevin »

Okay, I need to know if I have lost 27 years of modeling skills. I'm working on my first vinyl kit, Pegasus's Great White Shark. The head is molded separately from the body, and for some reason, I can't close the gap between the head and the body. I used super glue for the construction, but there was a slight gap. So I filled it with super glue, sanded, but there's still a visible gap when I spray on primer. I tried Squadron putty, but there's still a line. I tried Bondo Spot Glazing putty, but there's still a line. I tried super glue again, and still, line. Am I really missing something here? Is there some secret about vinyl that you can't fill gaps in it? I've tried everything, but it's starting to feel like the fish is laughing at me. Can anyone offer any insight that might help me deal with filling gaps in a vinyl kit?

Thanks
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Ziz
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Post by Ziz »

How are you sanding it after you apply whatever you fill it with? It's subtle but wrapping sandpaper around your finger so that it will conform to the surface when you press down is counter-intuitive. In reality, it conforms so well that it gets back into the seam and cleans out your fill work.

Wrap your sandpaper around a rod or small piece of wood block. Use that to sand ACROSS the seam, not with it. Then you'll be bridging the gap - you won't have anything sinking into the seam as you sand.
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Kylwell
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Post by Kylwell »

I'd take a guess that the sandpaper is sanding down either the fill or the surrounding vinyl faster than the rest. The way to solve this is a hard sanding surface like sandpaper glued to a popsicle stick.
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USSARCADIA
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Post by USSARCADIA »

It might be the vinyl is flexing slightly, two different materials. If nothing else works, try a little siliconized, paintable caulk, like DAP Alex Plus. Apply some on and wipe off with a wet rag, leaving a small amount in the crack and let dry. Then prime over and see what happens.
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Post by seam-filler »

As USSARCADIA says, it's probably the vinyl flexing and/or expanding/contracting at a different rate to the filler.

The trick is to use a filler that flexes/expands/contracts in a similar way to the vinyl.

And that trick is to use high-quality plaster of paris, but instead of making it up with water, make it up with PVA (white) glue - Elmer's is fine for this. It's best if the surfaces are 'keyed' first with CA.

Another alternative is to use a fine acrylic-based wood filler.
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Post by Valdore »

if the parts don't flex much at all. How about a mix of paint, and talc?

If the seam isn't structural. it should be usable. Basically, you mix the talc in to the paint ( I use acrylic over acrylic primer. though I'm not sure about enamel. ) until you get a thick sludge. let it dry ( it will shrink some. So reapplication will probably be needed. ) Once dried. Sand it down. the mix should sand down quicker than the surrounding, harder vinyl.

the great thing about this mix, is that it can be sort of colour keyed to the base coat. And if thick enough. can even be sculpted to match surrounding detail. I've used it on an old Godzilla kit years ago. And didn't even have to sand, or paint the seams. And its lasted about 10 years so far without any problems. Bonus. :D

I've used this mix on both vinyl, resin, and plastic. From Predators, to starships. And as long as the parts don't flex much, I've never had a problem with it.

Now, if I could only figure out how to connect my new phone, to my laptop. I might be able to show pictures about what I'm on about. Yeah. not ever gonna figure that out :roll: lol
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Post by photoguy »

Gorilla CA has micro-beads in it, and remains flexible once cured. I use it on vinyl all the time.
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Kylwell
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Post by Kylwell »

photoguy wrote:Gorilla CA has micro-beads in it, and remains flexible once cured. I use it on vinyl all the time.
Not really. The microbeads that is. It's simple a mix of powdered rubber & CA.
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photoguy
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Post by photoguy »

Whatever it is, it fills seams in vinyl, and sands pretty nice too. :P
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Kylwell
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Post by Kylwell »

Yup, love that Gorilla Glue. :D It's the only CA I use anymore.
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Post by Lt. Z0mBe »

Kylwell wrote:Yup, love that Gorilla Glue. :D It's the only CA I use anymore.
Used it for the first time this week. As for how I like it let me put it this way: If I were single, I think I would move to Maine or Massachusetts and marry it. :D

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Post by Whiteraven_2001 »

I'm happy to have stumbled upon this thread. I'm thinking of buying the Great White sometime soon, maybe with the first paycheck from my new job. :D
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Post by TER-OR »

Another tip I'll share - using something like Mr. Surfacer or another fillable primer type thing. Don't try to sand down to where you only see the filling in the gap. That's too far. Sand down until you have a smooth layer of the fill OVER the gap.

The rubberized CA does tend to avoid this problem a bit. Plus, it can be diluted with thin CA if you find it too thick.
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