Modeling putty?

[spookshow]

What's a good modeling putty for creating curvy locomotive features? I'm thinking specifically of something to blend the upper headlight of a Rock Island AB6 into the surrounding roof -



Thanks,
-Mark

[wazzou]

Mark -
I prefer Bondo Spot Putty.


It dries quickly, doesn't shrink and has great workability.

[71jeep]

X2 I have never had any luck with the hobby puttys I use automotive glazing putty and have had much better results.

[hpwrick]

Glad I tuned in here.    I will give Bondo, a try.   

I haven't been happy with the modeling putty.

[Catt]

+3,modeling putty does not work for me either.That tube of glazing/spot putty will go a long ways.

[Kev1340]

I use 'milliput' for that type of work, two part epoxy putty, the superfine is best. It adheres to all materials, is workable for 15 minutes or so and can be sanded once it has set.

Cheers,

Kev

[cholmes]

I have found A-poxy easier to work with than Milliput

[peteski]

If the curved feature is thick enough then none of the solvent-based putties will work as they shrink as they dry (and their solvent usually softens/attacks styrene).  It might look dry but it will be outgassing for a while and a month later (after your model is painted and finished) you can end up with softened paint or a depression in the area of where the thick putty was applied.)

Best is to use either a 2-part epoxy putty or simply Bondo polyester body filler.  These harden by chemical reaction so they don't shrink or take very long to dry.  From my experience Bondy filler is softer and easier to file/sand than the epoxy putties.  BTW, Tamiya also males their flavor of epoxy putty.  But the other ones already mentioned are also perfectly fine to use.

[Bobster]

Mark,
If it is still good I plan to use Milliput Superfine White on my N scale AB6. 
It has given me excellent results in 1/35th armor modeling. 
Kits I've built years ago have not had any putty shrink or cracking.

Bob

[spookshow]

Thanks for all the suggestions. I've never been particularly ept when it comes to epoxies where you have to mix two parts, so I think I'll give the Bondo a try.

-Mark

[LV LOU]

 Mark,I almost never use solvent based putty if I do use a filler of any kind,I usually make the part from solid plastic,and drop it in a hole I file out.If I do use solvent based filler,the only one I use is Tamiya,it has an aluminum base filler,so,minimal shrinkage,but I really only use it for small surface imperfections,not to actually build up anything..I sometimes use gel type polyester resin,although not very often,it's close to plastic when hardened...

[peteski]

Thanks for all the suggestions. I've never been particularly ept when it comes to epoxies where you have to mix two parts, so I think I'll give the Bondo a try.
-Mark

The Bondo body filler I mentioned is 2-part product (resin and hardener). You are probably going with the Bondo glazing putty (solvent-based), right?  But don't come back to us later crying about shrinkage - you've been warned.   

[spookshow]

I have people telling me about shrinkage and others telling me about no shrinkage - same product. God I love forums 

-Mark

[peteski]

I have people telling me about shrinkage and others telling me about no shrinkage - same product. God I love forums 

-Mark

Um, I didn't see any mention here stating that the glazing putty will not shrink (if applied in thick enough layer).  Simple rule of thumb is that any one-part putty which (by default) uses solvent which evaporates for the putty to harden will exhibit shrinkage. Liquid solvent was taking up some volume in the putty so when it evaporates, the putty volume decreases - it shrinks. In thin layers this is not a big problem but if you apply thickness of let's say 1/16" or more, it'll shrink as it dries (and it'll take a long time for the solvent to evaporate).

Any 2-part putties (or fillers) harden by a chemical reaction (instead of solvent evaporation) so even if there is some shrinkage, it is negligible.

That's all.

[LV LOU]

 Mark,even the best solvent based fillers will shrink,technically,even the two part fillers,epoxy,bondo,ETC,have a shrinkage factor,although it's miniscule on the level to which we use it.Solvent based stuff,however,shrinks a LOT.If it's 10% solvent,it pretty much shrinks close to 10%!! I was messing with a PRR BP20 shell,I used the Tamiya aluminum filler on the roof.Six months after I filled in the roof,I took it out to start working on it again,it looked like a little black & silver bannana.I gave up on it not because of that,but because I was having difficulty just getting F7 B units to cast without bowing because of shrinkage,an 8 inch long shell was gonna be a headache..