Ahoy ALL , The newest problem I am having problem with is, trying to figure out a non-destructive way to remove a silicon glued in mast sleeve .
I have already tried to heat the sleeved mast ends with heat guns, while using a two ton hydraulic jack to push the mast apart , but no joy ! That Dow Corning adhesive silicon sealant has a strong bond to the aluminium .
I had to saw through the sleeve to reduce mast length for shipping so now am faced with the problem of removing the half sleeves .
Will try to attach photos .
The obvious easy solution is to install another sleeve inside the glued one, but that would be my last resort remedy .
Doug,
How hot can you get the aluminum with heat guns? Would careful heating with small propane torches, using a flaring tip be possible? Maybe you could do a test and glue 2 pieces of Al together with silicon and see if heat will release them? I guess Al with its ability to conduct heat makes it hard to get something that large very hot? Maybe 3M knows some tricks for getting silicon apart?
Would using a Dremel tool VERY carefully allow you to remove a section of the sleeve at a time? A couple of grooves in the sleeve would let you to pry sections away from the mast. Dremel makes some models that are much more powerful than the little kit version that I have. I borrowed such a tool (which had a remote power head) from friends some years ago. I might be possible to jerry-rig a jig that would keep you from damaging the inside of the mast?
Is your mast in 3 sections, so you have 2 sleeve joints to deal with? I guess you cut the mast in 2 places, only 1 of which was at the sleeve.
Cured silicone rubber is soluble in diesel fuel, kerosene, and gasoline. Takes time (e.g. soaking for 2+ hours). And I would guess that the close fit of your mast sleeve would slow the process more, because the solvent just cannot get into the joint.
Note that WD40 and a number of similar products are extremely similar to petroleum distillate, in other words a refined version of diesel fuel.
Soaking or squirting (once you have an initial channel into the silicone rubber) are possible technique.
In Australia, the sealant company Selleys makes and markets a ‘silicone sealant remover’, which is a gel meant to be smeared onto silicone rubber used to fix plumbing devices or tiles or whatever to a wall. See: http://www.selleys.com.au/sealants/silicone/remover/. I don’t know the active ingredient in Selleys Silicone Remover, but I would guess a powerful solvent (? xylene) or just petroleum distillate (e.g. WD40). See the INFORMATION tab on that web page for hints.
when I was a young adult working in mining towns on the fringe of the Great Australian Desert, I’d bump into blokes who’d punctured their vehicle fuel tanks (gasoline or diesel). And then tried to plug the leak with silicone rubber, which never worked of course. I’d show them what my father had taught me - bar soap (ie soap sold in hard bars, as it was in those days).</personal story>
I’d try soaking in gasoline or diesel fuel first. Avoid using a heat gun while doing so. And if that fails, try the Digesil silicone stripper.
Re-reading the Selleys Silicone Remover web page and the Digesil page made me think they have more than just a petroleum solvent in their product. Probably an acid too.
Later addition: Digesil seems to be manufactured in the UK. The MSDS suggests it contains: Petroleum Distillate and Dodecylbenzensolfonic acid.
I think that’s a typo for sulfonic acid. A benzene sulfonic acid, in other words. It’s probably not a strong enough acid to etch your anodised aluminium, but I would flush your mast well with water once free of silicone rubber. And use protective clothing (I would guess that Digesil would dissolve rubber gloves!) for yourself. See Sulfonic acid - Wikipedia.
Good Morning Dan , T Y for your reply . I don’t think that only one method will be needed to remove that cut sleeve, but instead multiple methods will be required .
I did try to use two heat guns, one on each side, at the same time, but this only softened the silicon enough that the 2 ton hydraulic jacks would separate the joined pieces about 1/8 th inch, just enough to allow me to saw through the sleeve without scratching either mast butt end .
Later I found out that silicon melts at 2,577.2 degrees F , ouch , because the aluminum critically softens at 300 degrees F. Also , anodizing will be damaged from thermal stress if exposed to temps above 176 degrees F .
I have my Kett Saw, Fein tool, and Dremel tool at the ready, and will keep the forum informed of the results.
Good Afternoon to you Bil , nice to hear from you . T Y , for your research , I will make some tests with this new information . It was Jeffrey Leng , who advised me to use Turpentine to remove the silicon squeeze out from the sleeve jointing process.
I will also try some Digesil Silicon stripper, as it will be especially needed to remove the remnant silicone , before inserting the new sleeve. I will also try the Sulfonic acid , too .
Ah Ha !!! The old bar soap trick , doesn’t the US Military call that mixture Napham (sp-?)
I recommend you first try relatively inexpensive diesel fuel, gasoline or even mineral turpentine. If that does not deliver the goods, change to the more expensive Digesil.
Making a bath so the butt of the mast section can soak for 2 or more hours should loosen the silicon-aluminum join enough to move it. And even if each move is only incremental, you’ll soon win the fight.
Yes, soap dissolved in gasoline or diesel fuel is napalm.
If the proportion of soap is very much higher than the proportion of liquid fuel, the soap will be solid enough to block a leak. If the soap proportion is much lower, the result is a sticky and flammable gel.
My guess is that Digesil and Selleys Silicon Remover use the same (or a very similar) formula.
The benzene sulfonic acid will create an acidic environment and that acidic environment might be perfectly suitable for breaking silicon adhesion.
I also guess the benzene sulfonic acid will also act like a detergent, separating molecules with different polarity. So the benzene sulfonic acid might be important for stopping dissolving silicon rubber from repolymerizing and re-adhering to the aluminum of your mast.
