Large Scale Central

Warning - caution when using clear sealant on styrene plastic

General Discussion
#1

Found out the hard way to never use ordinary clear polymer sealant on styrene plastic. I always use a ‘neutral cure’ clear gutter sealant, but due unable to source, I went for the ordinary cure sealant. I am aware that it may cause rusting on steel but was horrified yesterday afternoon to find that it eats styrene plastic. My articulated mother hubbard is no more. I sealed two Bachmann Annie cast weights inside the body over the rear drive, nearly two weeks ago. This afternoon, I noticed a deformity in the body shell. The plastic was completely softened and in parts dissolved. A complete write off. Two weeks of work and several hundred dollars down the drain!!! One quarter of the boiler moulding was totally deformed and dissolved as if attacked by a solvent. The sealant used was a clear polymer ‘paintable’ type. Normal silicone cannot be painted after application. No warning on container apparent as regards use on plastic, although the writing is so small that a magnifying glass is needed to read the fine print.

I carried out a similar sealing/adhesive application about two years ago on my 4-4-4-0 Mallet with no effect on the plastic. The sealant used then was the neutral cure type clear silicone adhesive.

All I could salvage were the two drives, the cab and some detail bits. The rest is in the garbage bin.

#2

Whoa! Bummer to the max! Thanks for the WARNING!

#3

That really is a shame. :frowning:

Just try to look for a bright side… someplace… Maybe that it isn’t a ‘shelf queen’ anymore?

There’s a lot of things that give off VoCs as they cure that will attack other stuff, even stuff halfway across the room if it isn’t well ventilated… (paint or glue vapors “fogging” the windows on other models for instance) The label doesn’t always list everything, either. Sometimes you have to ask for the full data sheet - which many retailers won’t even have - requiring you to contact the manufacturer. If in doubt, test it on a sacrificial piece of scrap material first (the manufactures usually recommend this for legal reasons, anyway… that way you can’t say that they didn’t warn you).

Aaaaaaand, you probably already know this, but generally speaking, if you can still smell it, it isn’t done curing yet. And the chances still remain for a bad experience like yours…

#4

Whoops. Expensive lesson.
Not a total loss.
Take the good parts off and use the rest as a “crashed” display on the layout.
I have 2 Bachmann big haulers out on my layout under the bridges.

#5

John,
it is in effect a total loss as the drives, apart from stripping for spares, are suitable only for another articulated. I know that an articulated this length cannot be used on my curves, so building another articulated is a waste of time and money. It is a pity as the two drives were matched perfectly and the loco did track very smoothly.

I currently have four locomotives under construction, so will not dwell on the loss. Modelling can be a very steep learning curve.

#6

Oh no Tim :frowning:

#7
Tim Brien said:
I know that an articulated this length cannot be used on my curves, so building another articulated is a waste of time and money. It is a pity as the two drives were matched perfectly and the loco did track very smoothly.
Build a Garratt. It'll take the curves. http://en.wikipedia.org/wiki/Garratt
#8
Tim Brien said:
so will not dwell on the loss. Modelling can be a very steep learning curve.
Amen to that statement! Sorry to hear about your disaster Tim but appreciate you passing on the information. I wouldn't have thought of that one happening. Good luck with the rest of your builds. Rick
#9

Tim,
For what it’s worth, unless I can mechanically fasten weights in locos or tenders, I use clear silicone without any bad effects.

#10

(http://i271.photobucket.com/albums/jj131/soultraindart/Smilies/UselessWithoutPics_Happy.gif)

:stuck_out_tongue: Sorry, I just couldn’t resist.

#11

Tim, many thanks for the warning.
To Tim and others who know:
Asking for further information in addition to: “… never use ordinary clear polymer sealant on styrene plastic. I always use a ‘neutral cure’ clear gutter sealant, but unable to source, I went for the ordinary cure sealant.”

Please offer us a brand name so when at Home Depot the contents can be read to determine if the product is an “ordinary clear” or one of the “neutral cure clear” types.
I am not familar with the types.

Thanks,
Wendell

#12

Wendell.
product brandnames would be different in Australia. However, look for a product that specifies that it is ‘neutral cure’. I have used it for years on models and electrical boards with no problems. An ordinary cure sealant will release acetic acid (vinegar) smell and is corrosive to steel and electrical connections.

         The type that I have always used is intended for roof guttering assembly/repairs.  It is inert and does not react with the metal coating on guttering.  If it does not say neutral cure then assume that it is corrosive.
#13

Tim-
Thanks.
There’s a series of “Shoe-Goo” or “Goo” products – any experience with them?
Plus, a product calle E-6000 claims safe for photographs, paintable, non-flamable, and waterproof. Best guess on this one?
Wendell

#14

Wendell,
brandnames here in Australia are generally specific to us, although there are Bosch and du Pont brands, but have no experience with these as they are for the building trade. Basically, if it does not state ‘neutral cure’ then leave it on the shelf. I have used neutral cure sealant for years and have never suffered any degradation of base material.

The corrosive sealant that caused the problem, had no warning regarding usage on styrene, but as it is specifically designed for the bathroom/building trade, then usage on plastics was most likely not even considered by the manufacturer.