Came up with filler idea... looking for opinions.

CaptainHawk1 · Post by **CaptainHawk1** » Wed Feb 21, 2007 1:16 am

I'm currently working on the 1/100 AMT Enterprise B and after I got he 3 pieces of the lower hull together using Tenax, istrated the process of sanding her down.

If you've built this model you know that instead of one big piece like the Excelsior, this thing has 2 sides and a back piece (I believe that's where the lower hangar deck is).

Well, there was a good size gap (OK... hole) where the bottom of the backpiececonnects to the 2 sides. I was going to fill it with glazing putty and sand it down but while I was in the process of sanding the rest of the seams down where I had used Tenax, something magical happened. It seemed that all of the styrene dust had actually filled the hole for the most part and I applied a drop of Tenax on it to seal the deal and melt it.

Volia, no hole. As I didn't want to screw up a good thing, I simply sanded and used CA on the rest of what was left of the slight gap.

The question are A.) Can you by styrene dust or am I just going to have to make my own and B.) am I playing with fire using styrene dust and a Tenax as a filler?

-Shawn:smoke:

Shinnentai · Post by **Shinnentai** » Wed Feb 21, 2007 3:39 am

A) Don't think you can buy it, but you can make it easy enough by grating sprue on a sanding block.

B) Nope. It's perfectly cool. I "discovered" a similar method (using curls or slivers of shaved sprue instead of dust) while building Preiser adam/eve figures. It's a great method for solidly sealing large gaps.

I've also seen a tip for DIY putty, in which one chops up the kit sprue into a bit of MEK/Testors liquid cement, creating a thick goo of dissolved styrene for putty use. I've tried it, and it does work, although it takes forever to cure, and the puttied areas turn out slightly softer than the surrounding plastic.

Mr. Badwrench · Post by **Mr. Badwrench** » Wed Feb 21, 2007 4:01 am

Or you can buy Mr. Dissolved Putty, which is the same thing without the guesswork of "Do I have too much acetone? Too much sprue?" Dries faster too, about half an hour.

DX-SFX · Post by **DX-SFX** » Wed Feb 21, 2007 1:32 pm

It does tend to shrink though. Home made filler like this can can take weeks before it hardens out properly. You can sand it flush the following day and a week later it's sunk in through shrinkage. I don't think it's ultimately worth the effort. Superglue is better and quicker.

Post by **TER-OR** » Wed Feb 21, 2007 2:04 pm

The hot cements are great for this - you can put a shim in place, and cement it. Then sand the area down. If you do it well, there won't be any trace of a gap. Similarly for holes - a styrene rod - sanded-smooth sprue works great.

The powder might be tricky, but thin strips of styrene work well.

Treadhead · Post by **Treadhead** » Thu Feb 22, 2007 12:45 pm

I posted a similar thread in the General Sci-Fi section. I have a gob of fine styrene dust from sanding. From what you have said, I think that we are definitely on to something!

CaptainHawk1 · Post by **CaptainHawk1** » Thu Feb 22, 2007 10:07 pm

I was using strips and shims last night too for the first time... dude, styrene and hot glue are the way to go.

Hey, I'm curious does anyone know the difference between Tenax and the Testors model cement (MEK)?

-Shawn

Mr. Badwrench · Post by **Mr. Badwrench** » Sun Feb 25, 2007 6:33 am

Testors, as you say, is mostly MEK. Tenax, (and Ambroid ProWeld), is methylene chloride. Somewhat more dangerous stuff than MEK, but that's like saying a tomato is somewhat more red than an apple.

Shinnentai · Post by **Shinnentai** » Sun Feb 25, 2007 9:02 pm

Tenax is a hotter solvent. It bonds/sets quicker than Testors, and in my experience produces a stronger weld. Trade off is that it can melt or distort thin plastic if not used carefully.

CaptainHawk1 · Post by **CaptainHawk1** » Mon Feb 26, 2007 12:22 pm

Shinnentai wrote:Tenax is a hotter solvent. It bonds/sets quicker than Testors, and in my experience produces a stronger weld. Trade off is that it can melt or distort thin plastic if not used carefully.

Actually this is the effect I'm going for with my shims that I'm using to fill my gaps.

-Shawn

Shinnentai · Post by **Shinnentai** » Tue Feb 27, 2007 2:39 am

Yes, in this context it's an advantage. I've also found that this effect can be helpful when dealing with imprecise/mismatched mating surfaces. With proper clamping, the squishyness of the surface affected by the solvent can true the seam at the same time as bonding it.

Take the wings of the Revell Starfury for example. As is, the inside pieces of the main wings (the parts with the ribs, not the airfoil surfaces that attach over them) don't sit flush all the way around, due to imprecisions in the thickness of the parts: they stick up at some of the corners because the parts' undersides are too thick at the edge. Normally this would mean sanding or filing these areas 'till they sit flush. With a hot solvent like Tenax though, you can just wick a few extra drops into the seam to soften the underside, and compress it flush with a clamp 'till it sets. Neat-o, and effeciant!