jonhall Posted May 4, 2013 Share Posted May 4, 2013 I can't resist a bargain Airfix mk2, despite the fact I don't need them, whenever I see some cheap I invariably end up taking them home with me, so after the Epsom show last weekend I find myself with 9 that have been brush painted in intercity executive - so they needed to go into the paint stripper, the problem being I have hardly any in the house, certainly not enough for this number of coaches, and as it turns out my modelstrip has dried out entirely leaving a solid block of clay at the bottom of the pot. I've already worked out this stuff is mostly Sodium Hydroxide to do the stripping, with either Bentonite clay or a carbopol thickener to help it remain in contact with the painted surface, and I keep meaning to acquire some out of date Sodium Hydroxide from work, the difficulty is we seem to use it up before it goes out of date, so I needed to find another source. A quick search under the kitchen sink revealed Mr Muscle Sink and plughole unblocker, which would seem to be a likely candidate. My first approach was to fill a container with the MrMuscle and leave one end of the coaches soaking for a couple of hours, this is the result having proved the concept I then smeared it over the coaches, but them in a plastic bag and left them overnight - Alas whist it is quite thick, it still tends to drain away so I eventually settled on a plastic tray which seems to have done the trick. Needless to say I wore gloves, a lab coat and safety specs when doing all of this - and I can't offer any warranty about other plastics, but I'm sure someone may find this useful. Jon Link to post Share on other sites More sharing options...
meld Posted May 4, 2013 Share Posted May 4, 2013 Nice Work Jon, Thanks for sharing. Mike Link to post Share on other sites More sharing options...
Mark Saunders Posted May 4, 2013 Share Posted May 4, 2013 Personally I just use the Generic Sodium Hydroxide mixed with warm water in concentrated solution and put the item to be stripped in a tub and bathe it till the required result is obtained. Mark Saunders Link to post Share on other sites More sharing options...
DavidR Posted May 5, 2013 Share Posted May 5, 2013 I've been using oven cleaner to strip paint off Triang/Hornby clerestory coaches, for some years now - doing exactly what you have done: works like a dream. BTW, dont forget to rinse them thoroughly in cold water afterwards. Link to post Share on other sites More sharing options...
RMweb Premium Welly Posted May 5, 2013 RMweb Premium Share Posted May 5, 2013 Personally I just use the Generic Sodium Hydroxide mixed with warm water in concentrated solution and put the item to be stripped in a tub and bathe it till the required result is obtained. Mark Saunders Same here but I don't understand how sodium hydroxide "go out of date" at Jon's workplace - it's a stable compound! Link to post Share on other sites More sharing options...
jonhall Posted May 5, 2013 Author Share Posted May 5, 2013 Same here but I don't understand how sodium hydroxide "go out of date" at Jon's workplace - it's a stable compound! Yes, but sometimes its just what the paperwork says that matters.... Jon Link to post Share on other sites More sharing options...
cobach47 Posted May 22, 2013 Share Posted May 22, 2013 I have been using Mr Muscle oven cleaner for ages, just put the bits in a food bag, spray the cleaner over the bits and seal the bag leave overnight and rinse off using a old toothbrush this works best on enamel paint but will take off some acrylics. On the subject of paint stripping don't use white spirit on old models it ruined a prairie tank body by attacking the plastic, some bodies were still made with a acetate/ plastic mix. If you need more help get in touch Link to post Share on other sites More sharing options...
ess1uk Posted June 6, 2013 Share Posted June 6, 2013 now theres something to try at the weekend on an old Hornby class 47 body i have. thanks Link to post Share on other sites More sharing options...
DavidR Posted June 6, 2013 Share Posted June 6, 2013 now theres something to try at the weekend on an old Hornby class 47 body i have. thanks Don't wear your best suit, whilst doing this! Link to post Share on other sites More sharing options...
PatB Posted June 7, 2013 Share Posted June 7, 2013 There is something about that that scares me! Caustic Soda isnt something to splash about at the weekend...or ever for that matter....... Im not saying you dont know that, but this is the internet, where them who might not know that might go aaarghhh!! if they do splash it about a bit .... Whilst I agree that caustic soda, and any other hazardous chemical for that matter, needs to be treated with due respect I also worry that excessive caution regarding who may be reading forum posts may limit public discussion to only subjects which may be broached in the presence of a rather dim 5 year old. Meaningful exchange of ideas requires certain assumptions about the level of intelligence, competence and responsibility of potential readers. The only alternative that I can see is for all internet fora to require members to undergo the sort of mindbendingly dull safety induction which is now standard in industry. Link to post Share on other sites More sharing options...
RMweb Gold Phil Bullock Posted December 10, 2014 RMweb Gold Share Posted December 10, 2014 There are several paint stripping topics on here but landed on this one Needed to strip a Hornby Green Class 31 prior to respray in blue My usual model strip failed to shift the persistent body side stripes as did Mr Muscle and isopropyl alcohol Was resigned to Tcutting it all off but purchased some superstrip at Warley 20 minutes immersion and tooth brushing was all it needed! Certainly worth the investment but work in a well ventilated area. Phil Link to post Share on other sites More sharing options...
TheWeatheringMan Posted December 10, 2014 Share Posted December 10, 2014 There are several paint stripping topics on here but landed on this one Needed to strip a Hornby Green Class 31 prior to respray in blue My usual model strip failed to shift the persistent body side stripes as did Mr Muscle and isopropyl alcohol Was resigned to Tcutting it all off but purchased some superstrip at Warley 20 minutes immersion and tooth brushing was all it needed! Certainly worth the investment but work in a well ventilated area. Phil Hi Phil, A bit difficult to fathom this one out i'm afraid. The product you mention buying is, as i've pointed out several times before on other threads, overpriced Isopropyl Alcohol. Only thought I can offer is are you sure the IPA you tried was actually pure 99% - if its 'reduced' it smells the same but is vastly less effective. I use pure IPA (or the cheaper Denatured Alcohol) often for removing RTR finishes from my models with complete sucess. Regards Link to post Share on other sites More sharing options...
RMweb Gold russ p Posted December 10, 2014 RMweb Gold Share Posted December 10, 2014 Ive soaked several lima bodies in brake fluid in the past with great results, perfect yellow clean bodies Link to post Share on other sites More sharing options...
RMweb Gold Phil Bullock Posted December 10, 2014 RMweb Gold Share Posted December 10, 2014 Hi WM I work in a lab where there are gallons of IPA - yes 99% too - and for sure modelstrip aint just IPA, the smell and evaporation rate are evidence of that. I am not an analytical chemist but the contents are also listed as butoxyethanol and dimethylcarbonate - a quick google reveals the former as having surfactant qualities and having use in paint solvent systems whereas dimethylcarbonate is listed as solving most common resin systems. I suspect therefore that the IPA is there as a diluent to make the complementary action of these two rather more controllable. And it works where IPA does not - the photo is the evidence, plain IPA did not touch this Hornby paint. Kind regards Phil Link to post Share on other sites More sharing options...
TheWeatheringMan Posted December 10, 2014 Share Posted December 10, 2014 Personally I just use the Generic Sodium Hydroxide mixed with warm water in concentrated solution and put the item to be stripped in a tub and bathe it till the required result is obtained. Mark Saunders Hi, PLEASE TAKE NOTE OF THIS WARNING - NEVER, EVER mix Sodium Hydroxide (Caustic Soda) with warm water. Sodium Hydroxide is 'exothermic' - that is when mixed with water an exothermic reaction always takes place and considerable heat is generated. This heat can easily reach only just below boiling point of water from cold and if warm water is used its very possible the exothermic heat might cause a boil that will through boiling Caustic Soda everywhere with potentially disastrous results. Also never make the mix in an aluminium or aluminium alloy container. Sodium Hudroxide attacks aluminium and its alloys very violently and generates HYDROGEN gas. Combined with the exothermic heat you have the potential for an explosion or again a dangerous splattering. Mr Muscle is strong Sodium Hydroxide based and therefore works well to depolymerise paint and allow stripping and is probably one of the safer ways to use the chemical. What i've said above might sound frightening or off putting but these things are a worst case scenario if the chemical is used wrongly. Used sensibly by responsible modellers, as i'm sure RMWeb Members are, the chemical is safe enough provided the obvious safety precautions are taken. Incidently, Sodium Hydroxide can 'go off' Sodium Hydroxide, in both solid and liquid form, is also hygroscopic - that is it absorbs moisture and therefore can gradually weaken and degrade. Although in a sealed container this is less likely its the reason why 'use by' dates are specified in many cases. Please accept my appologies if my warnings above seem a bit strong but they are intended to prevent an accident and are based on my knowledge as a paint and solvents chemist. As I said, used by a sensible adult modeller for the purpose we are discussing there is no need to worry unduly. Hope the above is of help or interest. Reagards All. Link to post Share on other sites More sharing options...
TheWeatheringMan Posted December 10, 2014 Share Posted December 10, 2014 Hi WM I work in a lab where there are gallons of IPA - yes 99% too - and for sure modelstrip aint just IPA, the smell and evaporation rate are evidence of that. I am not an analytical chemist but the contents are also listed as butoxyethanol and dimethylcarbonate - a quick google reveals the former as having surfactant qualities and having use in paint solvent systems whereas dimethylcarbonate is listed as solving most common resin systems. I suspect therefore that the IPA is there as a diluent to make the complementary action of these two rather more controllable. And it works where IPA does not - the photo is the evidence, plain IPA did not touch this Hornby paint. Kind regards Phil Hi Phil, Thankyou for that. I know that when Precision in Cheltenham originally introduced the product it was as I described. As you will understand i've not bought any for years so clearly have missed it having changed. The properties of the other ingredients are within my training and qualifications. Again Thank You for correcting me on this point - although I still wont waste my money on the product having access to far more potent plastic safe finish remover!. Best Regards Link to post Share on other sites More sharing options...
RMweb Gold Tony_S Posted December 10, 2014 RMweb Gold Share Posted December 10, 2014 Hi, ... Incidently, Sodium Hydroxide can 'go off' Sodium Hydroxide, in both solid and liquid form, is also hydroscopic - that is it absorbs moisture and therefore can gradually weaken and degrade. Just in case anyone is researching this further, it is hygroscopic. Link to post Share on other sites More sharing options...
RMweb Gold Phil Bullock Posted December 10, 2014 RMweb Gold Share Posted December 10, 2014 Apologies for confusion folks - I have inadvertently deleted my post 16 above! WM has kindly quoted it in 18 above but that means I cant correct my error - I am talking about superstrip which is a solvent based system, not modelstrip which is an alkali based paste Cheers Phil Link to post Share on other sites More sharing options...
TheWeatheringMan Posted December 11, 2014 Share Posted December 11, 2014 Just in case anyone is researching this further, it is hygroscopic. Hi, Correct of course. Sorry about that - another slip of arthritic fingers on this ruddy touch screen tablet. Regards Link to post Share on other sites More sharing options...
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