Hobby Boss plastic problem ?

[Mu17]

A contact in Germany has described the sinking of a Hobby Boss plastic warship, converted to RC.

 

Allegedly the plastic distorted , bulged and split because of contact with water - which seems highly unlikely to me.

It was also claimed that normal 'hobby paint' (sorry not specified further) attacked the plastic !

 

More realistically I have heard some rumours that the mould release agent used by Hobby Boss can be difficult to remove - any suggestions ?

 

As I have bought the Hobby Boss Mikasa and intend to sail it with rc, I would be most interested to hear of other modellers experiences - do any such problems exist ????

Or as I suspect, is this a problem caused by failing to remove the release agent ??? 

 

Many thanks

Paul

[Mike]

I've fondled my fair share of HB plastic over the years and never had an issue with mould release or warping. Sounds to me like some kind of heat issue in the workings, or a reaction to some external factor. Puddle of fuel on the surface or summit?

[Rob G]

Photos or it didn't happen.

 

If it was powered by LiPo cells and they got wet, THAT would make things distort - those suckers get hot when they're used improperly.

 

Hobby paint - possible, but so unlikely as to be improbable, even it was a lacquer.

 

Mould release - possible. Still, a good soaking and scrubbing in strong detergent should put paid to almost anything. (I do recall reading about this somewhere, but I believe that that was very early production issues.)

 

For the plastic/water thing, cut a bit off and let it sit in the sink overnight. If it survives (which I'm sure that it will), it should be ok. I've seen some odd things in model boxes, including plastic that had gone crumbly (but that was a kit from the 50s), but never water soluble plastic.

 

Converting static models to RC isn't always as easy as it looks. Without further evidence, I suggest that either the battery got hot through improper cooling, or there was a water leak and the battery got hot... both events lead to the same result. After the sinking, the owner decided to slip the blame and started making noises about the quality of everything else apart from his workmanship.

 

As I say, photos or it didn't happen. Surely someone was there with a mobile phone.

 

[VMA131Marine]

What type of motor did he use? Those 380 and 540 size hobby motors generate a lot of heat and in an enclosed compartment without cooling could easily get hot enough to cause plastics to warp.

[johnd]

I've made a few of theirs over the years. They've been sprayed with car paint, brush painted with enamel (Colourcoats) and acrylic (Vallejo and Humbrol) and never had a problem. My modelling is pretty slapdash and rarely are the kits washed first. An isolated incident in unusual circumstances it seems.

 

John.

[spitfire]

My last two builds were Hobbyboss 1/32 scale Spitfires and I had no problems with the plastic and I did not wash the sprues before construction.

 

Cheers

 

Dennis

[bzn20]

I heard it was a 1/72nd Resin Torpedo from Anigrand wot dunnit.

[SleeperService]

Not a ship modeller but we've a lot of Trumpy/HB builds under our belts in my club. The mould release problem does still happen but, since we all started washing the plastic the problems with glue failing and dodgy paint have vanished.

As for styrene dissolving in water, the recycling industry would pay a fortune for that knowledge.

 

I should add that I've a 1/350 Dreadnaught to build. My Granddad served on her until he retired in 1913 to marry my Grandmother. Civilian life didn't last long.

[Jamie @ Sovereign Hobbies]

I've never washed platform. Mould release agent is a real thing for cast resin, but pretty much bunkum for injection moulded plastics.

 

As for hobby paints - I find that incredibly hard to believe however the hobby paint manufacture can make recommendations but ultimately has no control over what random liquids the end user takes upon themselves to use as a thinner. There is always some clown  trying to save on 50p worth of bespoke thinners and will use automotive gun cleaner instead, for example, then they get all upset when they ruin their work.

 

I agree with the above. I've never dabbled in r/c ships but am quite experienced in r/c aeroplanes. Electric motors, batteries and speed controllers are all prolific producers of heat - the motors and speed controllers concentrate it especially. Good (forced) cooling is very important.

[spitfire]

As an addition to my comments above I also painted the kits with enamel paints onto the bare plastic with no primer

 

Cheers

 

Dennis

[SleeperService]

Well there is/was certainly something on HB/Trumpy plastic that caused issues. I assumed it was a mould release agent but it could be anything. The paint was thinned using the proper stuff both acrylics and enamels including Sovereign would give a 'streaky' finish (even when sprayed) or white spots would appear in the finish after a few hours. 

 

Whatever it is washing the plastic stops it.

 

BOT I'd like to see a picture of the 'dissolved' plastic. I can't see how heat would do this, or even battery contents in a short time. 

[Jamie @ Sovereign Hobbies]

7 hours ago, SleeperService said:

Well there is/was certainly something on HB/Trumpy plastic that caused issues. I assumed it was a mould release agent but it could be anything. The paint was thinned using the proper stuff both acrylics and enamels including Sovereign would give a 'streaky' finish (even when sprayed) or white spots would appear in the finish after a few hours. 

 

Whatever it is washing the plastic stops it.

 

BOT I'd like to see a picture of the 'dissolved' plastic. I can't see how heat would do this, or even battery contents in a short time. 

 

Do these kits fall into a particular time period? I've painted loads of Trumpeter plastic with our paint and haven't noticed anything different from anyone elses' plastic?

[SleeperService]

1 hour ago, Jamie @ Sovereign Hobbies said:

 

Do these kits fall into a particular time period? I've painted loads of Trumpeter plastic with our paint and haven't noticed anything different from anyone elses' plastic?

As I stated above Jamie it was a problem, then we started cleaning the plastic and it hasn't reoccurred. It was longer ago than I thought about 4/5 years. Talking to a friend in the injection moulding industry there are several things that could be happening including, but not limited to;

oil mist from general machinery operations collecting on uncovered mouldings

fumes from the plastic being trapped by the heat sealed baggies and causing a deposit

model-makers with oily skin

a leak from equipment not being noticed

 

He thinks poor safety and maintenance procedures most likely although things aren't as bad as they were. Knowing model-makers I suspect unwashed hands myself.

 

Yesterday I opened a newly brought Roden kit and it smelt strongly of ear wax that got washed. I have a Trumpy Su-9U recently brought in sealed bags I'll get that on the build pile and see what happens.

   

[Mu17]

Thanks for all the comments guys - same conclusion as me - bunkham.

 

Sadly I can't get any more information, other that parts of the hull bulged slightly ! in addition to minor cracking.  

To me that sounds like a reaction to unsuitable putty / filler.  

 

Incidentally - whats the most effective substance to use to give the plastic a good scrub ??

 

Thanks again

Paul