Randy Taylor Posted May 14, 2005 Share Posted May 14, 2005 I just siliconed a 68uf solen cap to a small radio shack circuit board (I used a lot),that I was going to mount in my Heresy II as part of the crossover network. I was going to wait until the silicone cured (a few days) and than mount it in the speaker, but I read where silicone can be corrosive over time. I used Dow chem. 100% silicone (clear), and only used it on the cap and the board, it is not on any metal parts or is it the fumes that are corrosive even after it cures, I would hate to hurt any speaker windings, or other metal parts in the inside of the HeresyII encloser, did I mess up? Quote Link to comment Share on other sites More sharing options...
djk Posted May 14, 2005 Share Posted May 14, 2005 Did it smell like vinegar? If so, let it cure for several days. You could even put it in an oven and bake at 150*F for an afternoon to be sure its done outgassing. Quote Link to comment Share on other sites More sharing options...
dragonfyr Posted May 14, 2005 Share Posted May 14, 2005 Typically it shouldn't be corrosive after the curing process, but I do know that some types are reactive with respect to some of the solvents duing cure, while others are not, as evidenced by the 'safe' and 'unsafe/toxic' versions of silicone used in applications such as aquarium repair... Good question! Does anyone know just how to distinguish the types based on the labelling? Quote Link to comment Share on other sites More sharing options...
boom3 Posted May 14, 2005 Share Posted May 14, 2005 Dow is the stuff to use. The GE consumer products have changed over time, for the worse IMHO, and I don't use them for technical applications. The bad thing about using viscous sealers to mount parts is that when you go to remove them, you must slip a blade between the component and the mounting surface, and the 'glue' stays on both pieces, pretty much forever. This is why I use clips or wire ties (with cushion tape if mounting capacitors) for my projects. Quote Link to comment Share on other sites More sharing options...
boom3 Posted May 14, 2005 Share Posted May 14, 2005 Dow is the stuff to use. The GE consumer products have changed over time, for the worse IMHO, and I don't use them for technical applications. The bad thing about using viscous sealers to mount parts is that when you go to remove them, you must slip a blade between the component and the mounting surface, and the 'glue' stays on both pieces, pretty much forever. This is why I use clips or wire ties (with cushion tape if mounting capacitors) for my projects. Quote Link to comment Share on other sites More sharing options...
Randy Taylor Posted May 14, 2005 Author Share Posted May 14, 2005 The 68uf cap I'am using is big and heavy (about as big as a small spray paint can) and I didn't want it to fall off the cicuit board and be rattling around inside of the speaker when the speaker is moved around during the next fifteen years or so, I'am also going to wire it on the board for added support, I plan to do this crossover upgrade only once, and hope it lasts the life of my speakers and my ears, I'am 54 now and I guess when I'am in my 70s I won't be doing a whole lot of rock and rolling with my cane. or maybe I will! Quote Link to comment Share on other sites More sharing options...
sunnysal Posted May 14, 2005 Share Posted May 14, 2005 it CAN be corrosive during the curing process! it gives off acetic acid (that is the vineager smell) which can corrode metals, etc. if in a less than well ventialted area or in direct contact with metals. best bet is to try to buy the non-acid types (which can be found in electrical supply houses) or keep the thing is a good open area until fully cured. regards, tony Quote Link to comment Share on other sites More sharing options...
Marvel Posted May 14, 2005 Share Posted May 14, 2005 Some of the RTV (Room Temperature Vulcaninzing) Silicones are non-corrosive, even those made by GE. You just have to make sure you get the right kind. You need to look for those specifically made for the electronics industry. You could use Dean's Quart-O-Hotglue method... Marvel Quote Link to comment Share on other sites More sharing options...
colterphoto1 Posted May 14, 2005 Share Posted May 14, 2005 WHen I worked for Gates Learjet, yes THOSE jets, we had several RTV compounds (room temperature vulcanizing for you propeller heads) known as silicone, There is high strength, high temp, and specialty NON-CORROSIVE ones made for use around electrical components. This would lead one to believe that standard RTV's are somewhat corrosive. Michael Quote Link to comment Share on other sites More sharing options...
dodger Posted May 14, 2005 Share Posted May 14, 2005 The silicones we have here state whether they are corrosive or not. That was compliments of our Attorney General. I'll try to track some names of those that are not. Quote Link to comment Share on other sites More sharing options...
WMcD Posted May 14, 2005 Share Posted May 14, 2005 I wouldn't doubt that the acid type outgassng can corrode some metals. Copper may be one. OTOH, I see RTV used in general to caulk faucets, water valve collars, sink drains. There does not seem to be a problem. Granted those metal units are usually chrome plated. Maybe we should do an experiment and put some on a bright copper penny. Gil Quote Link to comment Share on other sites More sharing options...
Marvel Posted May 14, 2005 Share Posted May 14, 2005 This is what I was looking for originally when I was going to repair the surrounds on a set of JBL woofers I used Weldbond per DJKs's advice, and they are working great. One part RTV - non corrosive, by GE: RTV Quote Link to comment Share on other sites More sharing options...
Randy Taylor Posted May 16, 2005 Author Share Posted May 16, 2005 Well, I guess I did use the wrong silicone for mounting the big cap. to the new circuit board, but it has been a few days since I did it and it is stuck on there good, not coming off, and it is cured , not smelling any more, I guess it is alright to mount in my Heresy II. I guess if anyone thought I really messed up using it, and it would hurt things over time I could cut it off with a knife and mount it on another radio shack circuit board using the right stuff when I found it. But from what I under stand if the silicone is not hitting any metal and it is fully cured I'am OK. Quote Link to comment Share on other sites More sharing options...
djk Posted May 17, 2005 Share Posted May 17, 2005 "One part RTV - non corrosive, by GE:" The "fast cure" time is 72 hours! It may take a week or longer if the relative humidity is low. At work we put goods to be cured in a 60% RH chamber for anywhere fron several hours to two days. Quote Link to comment Share on other sites More sharing options...
Randy Taylor Posted May 17, 2005 Author Share Posted May 17, 2005 I siliconed the cap to the board Friday afternoon and it seems now to be completely cured, so I guess it is safe, but I'am going to wait another day or so before I install it inside the Heresy II, no point in rushing it now. What I love about silicone is once you use it to bond something together, its not coming apart unless you cut it off with a very sharp knife. Quote Link to comment Share on other sites More sharing options...
Tubes Horns and Buds Posted May 18, 2005 Share Posted May 18, 2005 Most RTV Silcones are corrosive and are acetic acid based. GE, Dow and Loctite all have non-corrosve versions that are oxime based. Look for Loctite High Performance at Home Depot or an Automotive store. Quote Link to comment Share on other sites More sharing options...
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