Putty Tip

[Rokket]

Just read this i Sept Finescale Modeler: a fellow seals big seams with Squadron White putty - but he dilutes the putty with liquid cement! I don't really know what he means, but it seems easy t experiment. Anyone ever do anything like this?

[Pat]

I usually seal the seams on plastic with liquid cement (styrene plastic glue) with small shavings of plastic mixed in. 

The way the glue works is that it melts the plastic and it runs together and welds as it hardens.  So if the seam is too wide or deep enough to leave a little valley, the added plastic helps it fill in and even out without using too much glue and melting the plastic too far around the seam.

A needle point file smooths it out if needed.  (I have a collection of about about 20 different different files shapes to get into almost any area.)

The same things for holes, such as filling in the diagonal line of too-large holes at the bow of the Revell 1:72 U-boat.  A small bit of waste plastic sprue in the hole followed by a drop of glue and the next day after it's completely hardened, just sand/file it smooth. 

[robtmelvin]

I've had good luck so far using "Bondo".  Not the two part stuff but the kind that comes in squeeze tubes you can pick up at Wal-mart or any auto parts store.  Heck of a lot cheaper than hobby specific putties and fillers and seems to work great.
Hope this is of help.

Bob

[Rokket]

Yes, never used Bondo but have seen it used on cars. I should give it a try.

Pat - the shavings Ive alsways wanted to try, but have also wanted to grind plastic into a rough powder for the job. Trouble is, I can't find a grinder that will do the trick (I id some damage to my wife's spice grinder...)

[Pat]

I'd never thought of grinding the plastic, but that seems like a reasonable method although I can see the problem with finding an appropriate grinder.

A possibility would be to use the coarse rasp and put a pan underneath that the styrene "sawdust" can be collected in as you rub it over the rasp.

I use a somewhat similar technique when making wood decks or other fittings for a wooden model.  The decks or hulls have to be sanded smooth once shaped.  I always do the sanding over a plastic sheet and then collect the sawdust into pill bottles.  Each bottle is labeled with the kind of wood used, and when needed to hide a seam, I can match the sawdust to the wood type.  I put a bit of carpenter's white glue across the seam and then sprinkle sawdust on top and rub it in.  The sawdust matches the wood colour, thickens up the glue to fill the seam and if done right will even take stain the same as the real wood.  It makes for almost invisible seams.

This should work for plastic too.  Just use different files / rasps to get different sized "sawdust" from the plastic for different uses.

[Mike K]

If you need plastic filler, use the sprue from the kit. That way the colors match.
Just cut the sprue into small pieces and drop them into a <>half bottle of "Tenax 7" ( or some other liquid plastic glue). Then give it a day or two, to melt. The more sprue you add, the thicker it gets.
Use cellophane tape on the outside, to hold it in place, and put it on in thin coats. The thinner the coat, the faster it sets up. The thicker the coat, the more likely the chance it'll melt, and deform, the plastic around it.
When sanding and polishing is finished, there is no detectable seam. And, it's as strong as the surrounding plastic.

Mike K.

[Rokket]

Thanks Mike! I like it! I shall get some Tennax next time at the LHS, and start experimenting...

[iceonaboy]

It might be an idea to save the shavings from the oil canning phase, as I seem to be up to my    in them!

[Rokket]

actually, yes, very much so! they would dissolve well, too, being thin

[OldNoob]

I wonder if regular old Testers model cement would work

[42rocker]

Several good ideas here. I normally back stroke areas that I need to bring down with my knifes and make a lot of fine scraps. I'll have to start saving some of that and try adding glue and using it for filler.
Thanks for these ideas.

Later Tim

[42rocker]

While eating lunch at work I review some of the interesting old stuff.   
 
Rokket 
Grinder - I have a nice black pepper grinder on the dinning room table for fresh pepper that runs out of pepper corn, so wife always seems to get more pepper corns that always come with a new plastic (cheap looking) grinder. I take it apart for the new pepper corns and have an extra grinder. Normally gets thrown away. I think that I'll save the next one and see if it will grind plastic cuttings from the spruce trees the parts come on. 
 
Later Tim

[Rokket]

let us know!