James G Posted February 28, 2017 Share Posted February 28, 2017 I had not come across this phenomenon before - hope it does not affect any of you! http://www.ratomodeling.com/articles/lead_ca/lead_ca.html Link to comment Share on other sites More sharing options...
allyby Posted February 28, 2017 Share Posted February 28, 2017 That is some series damage, I'm finishing of a model just now that called for a lead weight, luckily for me I hadn't any so just used blue tac instead. Link to comment Share on other sites More sharing options...
Mike Posted February 28, 2017 Share Posted February 28, 2017 I sometimes use CA with lead, but I guess we'll find out what the score is in 5-10 years. For the Mig-25 I'm building at the moment, I've dumped the lead in a load of Gorilla Glue and left it nose-down to dry. Then I covered that with a thin layer of CA to prevent fly-aways. Hopefully, a conical nose cone would just end up slipping back as it grew larger, and as long as it has somewhere to go it won't cause such catastrophic damage. We can hope Link to comment Share on other sites More sharing options...
Skodadriver Posted February 28, 2017 Share Posted February 28, 2017 That Heinkel is some mess! I always make my weights out of self-adhesive lead strip which is used by stained glass artists. It's sometimes possible to fix the weight in place with its own adhesive but if not I use BluTack to secure it. Some of my models are nearly 20 years old and I've never had anything nasty seep out or anything else bad happen. Link to comment Share on other sites More sharing options...
Graham Boak Posted February 28, 2017 Share Posted February 28, 2017 I've never encountered this and, although I can't quote chapter and verse, I'm sure I've kept examples longer than 5-10 years. The only disaster I had was then I used too much glue in the nose of a MiG-17 and it melted the plastic. This isn't likely to happen with the wider range of modern glues. Link to comment Share on other sites More sharing options...
Beardie Posted February 28, 2017 Share Posted February 28, 2017 The problem is that CA contains a quantity of sulphuric acid (that's why your jeans smoke if you spill it on them) and this will react with the lead to form white lead sulphate. As time goes on the lead will 'puff up' with sulphate and, if there is any moisture around, you will also get lead oxide. I would reckon that the only way to avoid this would be to coat your lead in some form of lacqeur prior to glueing in. Even with white glue,or blue tack, you will get oxide forming from the moisture in the air if the seal isn't complete but it will be a much slower process. Using a lump of lead rather than shot and securing it with silicon would also be a better option as one lump of lead doesn't offer the surface area for corrosion to form that a handful of shot does while silicon will allow for a degree of expansion of the lead that a hard glue wouldn't. Link to comment Share on other sites More sharing options...
Scimitar F1 Posted February 28, 2017 Share Posted February 28, 2017 I think that you can have problems with PVA as well as I have experienced something similar in a F-84 with PVA and was told that Cyano was the way to go! Will Link to comment Share on other sites More sharing options...
bentwaters81tfw Posted February 28, 2017 Share Posted February 28, 2017 I knew of this. I tend to use Customs lead trailer seals, or sheet flashing offcuts from roofing jobs, which I fix with double sided sticky fixers, or sometimes box in lead with lengths of sprue. If I'm using shot, it mix it with PVA, and block it in with a bulkhead if possible. Even my old builds are fixed with epoxy rather than CA. 1 Link to comment Share on other sites More sharing options...
LotusArenco Posted February 28, 2017 Share Posted February 28, 2017 I remember reading about this a while back. This, and ‘lead rot’ relating to older wargames figures with a large percentage of lead in them. Not experienced it myself, but better safe than sorry. I’m guessing most fishing weights these days are lead free? (One day I’ll sort out that Me262 on my shelf with it’s nose in the air ) Mart Link to comment Share on other sites More sharing options...
pigsty Posted February 28, 2017 Share Posted February 28, 2017 The last time this problem was aired, the consensus seemed to be that the most inert way to fix your weight - as in, no chemical side-effects at all - was candle wax. That's certainly what I use now. 2 Link to comment Share on other sites More sharing options...
Beardie Posted March 2, 2017 Share Posted March 2, 2017 The main thing I think is not to secure it to a seam or filling an area so tightly that it doesn't have room to expand if it corrodes, after all it won't expand that much. Rubber cement is probably the best fix giving flexibility and being stable in regard of heat and cold . Previously I suggested silicon sealant but I forgot that it contains acetic acid so you would end up with lead acetate corrosion instead of lead sulphate and be in the same fix as with superglue. Link to comment Share on other sites More sharing options...
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