Archive for The Unofficial Mamod and Other Steam Forum The Original Unofficial Toy Steam Forum Established 2006 The biggest, most popular steam forum around! Accept NO imitations! We have a growing community of regular posting members who chat about all aspects of toy and model steam.          The Unofficial Mamod and Other Steam Forum Forum Index -> Technical tips, Details, Home Builds and Help Me!! Wallace Dezincified boiler pics Finally got decent pics of my dezincifed boiler/s. As a few people have PM'ed asking what it looks like, and concerned about spots on their boiler, a bit of info first (I know many have heard it, but for benefit of thread). My leaking boiler came to me from my workmate. His engine had been fired a bit, but not much. Dropped on overflow plug and, and dented the boiler. Badly repaired, fired again, then sat for 25yrs approx, untouched. When I got it, there was still mositure in boiler. End cap, in dezincified bits, had white spots on it that came off with a wipe of the finger. I cleaned and polished the boiler, did not noticed copper colour much, it was/would have been much lighter. Probably thought it of being a "mark" in the boiler. Fired it, and when it got to operating pressure, it leaked, fine spray of water, so hole isn't large. Hole doesn't actually let water through when not under pressure, and holes aren't visible. The strong copper colour wasn't this bad after being polished, and was first noticed when I noticed the leak. ie, it showed up only after heat. Here's a link about dezinciification http://www.corrosion-doctors.org/Forms-selective/dezinc-valve.htm Other notes. * I never finished cleaning up overflow plug end as it's stuffed, so the silver on it is solder. * I have said in other threads that there was pitting. Well on the leaky boiler, there really isn't. Just one dot, that I will point out in pic. The other boiler, that I show, has got pitting. Just read descriptions under each pic This is the leaky end. Where the arrow points too is the only sign of a pit mark. It leaked in that area, and further toward the bottom of the boiler. The copper colour says it all The other end of same boiler. Arrow 1 points to yet another copper colour, but it didn't leak there. Arrow 2, is where the boiler leaked on this end cap. Only slightly there though, very light weeping. Pic doesn't show up the copper colour there as it was in the edge of the ridge 3 boilers I have. 1st one is the leaky one. 2nd one (MM2) shows copper spots, and these ARE pitted. I am yet to test it for pressure, in a real test. Firing. 3rd one (MM2) should be ok. Only a slight copper patch. I will test the untested pitted boiler soon. Anyway, hope this helps in identifying it. Not scaremongering here, but something to watch for. I know for one, that if in any ebay pic there are signs of it, I will not buy. That's just me though. I would be very cautious of any engine that states the overflow and safety valve is stuck, and hasn't been fired in a long time, as this will probably mean moisture in boiler. Basically the situation I had. Cheers guys tmuir Wallace I would try poping the end cap off th leaking one and silver solder a patch over it and then soft solder it back on. By silver soldering you dont have to worry about your patch coming off when you solder the end cap back on. Wallace tmuir wrote: Wallace I would try poping the end cap off th leaking one and silver solder a patch over it and then soft solder it back on. By silver soldering you dont have to worry about your patch coming off when you solder the end cap back on. Cheers tony. It is something I thought of, but didn't think of silver solder. Both end caps will have to come off. I'll put it on the "to do" list Might try the MM2 tomorrow, and will post results here. mj When you see 'dezinced' boilers on ebay they often show up as white or green spots. The copper shading only usuall shows up well once the boiler been polished up a bit. I'm sure that the end caps are more affected because they are thinner than the cylinder wall, & possibly made of a softer lower grade alloy that makes them more malleable & easier to stamp/press into the cap shape. Wallace Good point about the white or green spots. I'm going to try polishing the copper area, out of interest, cos it didn't really become noticeable until I steamed it. On the MM2 boiler, with the copper dots, it was there when polished. Might be best for us to ask for pics of end caps on any suspect boilers Sandman Notice how minor boilers are more prone than others to this particular disease. Wonder if it has something to do with the manufacturing process??? mj Sandman wrote: Notice how minor boilers are more prone than others to this particular disease. Wonder if it has something to do with the manufacturing process??? When i was was looking for an se3 a while back, most that came on ebay seemed to have the 'measles'. The quality of alloy varied greatly from batch to batch & mamod weren't known for there scientific approach to the design & manufacture process, 9steve malins has a little to say in the bible about it). Local water conditions probably have the greates effect on the life of a boiler. DZR fittings are commonly used in plumbing where the water exceeds 50C or there are known mineral problems (i.e. untreated private water suppplies). Steve_S This is a very interesting thread. It's not a problem I've had up to now, but now I know what to look for. Thanks Wallace. Mamodman123 I have had it on some of my engines that ive sold on. I managed to polish most of it out though. I guess it depends how deep its got in the boiler? I'm trying to remember if the Minor boilers are thinner than the likes of the SE3 but I can't There's one thing I can say, ive never seen it on an SP model, so it could be something to do with the age? SPOKESMAN Its age related MM. MTA I remember when I was bidding on an SE3, I was looking for others incase I lost that one. I noticed one that had dots all over the end cap nearest the chimney that were white with a purple rim around it Mamodman123 My Bowman had quite a lot of it all over the boiler but it polished out well! Things age and decompose i guess, not much you can do apart from look after them. Maybe in 10 years time we'll be seeing the SP range with the same problem? Roly Williams Mamodman123 wrote: I have had it on some of my engines that ive sold on. I managed to polish most of it out though. I guess it depends how deep its got in the boiler? I'm trying to remember if the Minor boilers are thinner than the likes of the SE3 but I can't There's one thing I can say, ive never seen it on an SP model, so it could be something to do with the age? It's obviously something that takes time to happen. Things like storage conditions and water quality will accelorate the process but it's not going to happen overnight. Another posibility is that Mamod may have changed the source and composition of the brass they used - especially after they changed hands so often. Mamodman123 Roly Williams wrote: Mamodman123 wrote: I have had it on some of my engines that ive sold on. I managed to polish most of it out though. I guess it depends how deep its got in the boiler? I'm trying to remember if the Minor boilers are thinner than the likes of the SE3 but I can't There's one thing I can say, ive never seen it on an SP model, so it could be something to do with the age? It's obviously something that takes time to happen. Things like storage conditions and water quality will accelorate the process but it's not going to happen overnight. Another posibility is that Mamod may have changed the source and composition of the brass they used - especially after they changed hands so often. Very possible Roly! I think a lot of engines you will find are stored in damp lofts, maybe even outside in garages, sheds etc. So it's quite easy to see how some of this stuff happens. I've not had an extreme case of this on a Mamod, but I've had an SE1a that was pretty bad. That was at least late 60's-mid 70's SPOKESMAN I have some of that copper spotting on one of my Older MM1s. Wallace Yeah it's all strange, and I seem to have copped the dodgy boilers I do have other boilers with dark spots, which don't polish out, but I'm not worried. Actually I think on of the MM2 boilers in the pics show a dark spot. But certainly something for us to look for. BTW, thanks to whoever originally mentioned this problem on these forums. It was ages ago, maybe even on old forums. But their words were something like "I have seen mamod boilers looking like swiss cheese"? If whoever said it, please own up Cos I'd like to thank you. It was only cos of them I know about it, as I mentioned it to my brother and described it as something that "rots the boiler and had a scientific term". He said dezincification. The net did the rest for me flywheel61 I also wonder where the flux goes on the engine may be a part of some of the non-dezincification copper spots on engines. I have several engines where there are copper spots well away from the soldered ends. If the fux hasn't been cleaned off properly and the lacquer is applied over the top maybe there is a reaction over time between the fux & the brass. May also be worth metioning dezicifation in Roly book if not already in there. Am still eagerly awaiting my copy by airmail. Cheers Chris Wallace Re: Dezincified boiler pics Wallace wrote: Just out of interest.... Ignoring the numbers in these pics, the 2nd, and 3rd boiler in the pic were tested the other day, and were fine It is only the first one that ever leaked. Umm, this was just an update for anyone who is interest Mamodman123 The first one looks quite severe wallace I've seen that all before, but that is an extreme case tmuir Glad to see the others were ok TE1A_man Re: Dezincified boiler pics Wallace wrote: Wallace wrote: Just out of interest.... Ignoring the numbers in these pics, the 2nd, and 3rd boiler in the pic were tested the other day, and were fine It is only the first one that ever leaked. Umm, this was just an update for anyone who is interest I am, i believe that my bing has that all over the boiler, when i shined it up, it looked like it was copper under the boiler, it may be just that the boiler was made of copper. Wallace Others here would know more TE1aman, but I am pretty sure the Bings do have a copper boiler, so that is fine. Also, as mentioned in thread, this severe copper colour didn't appear until I actually was in the process of raising steam. Tony, thanks for you comment (re glad to hear others were ok). I was too. With the pitted boiler I was actually expecting a small hole to suddenly "pop". Mamodman123 Some of mine had that on them Wallace, mostly the Bowman and a few flat faced SE3 boilers! Most of it polished off though! I guess you need to assess how severe its affected the brass?        The Unofficial Mamod and Other Steam Forum Forum Index -> Technical tips, Details, Home Builds and Help Me!! Page 1 of 1