Silicone; Dont use it and why.

[Jack Tar]

Silicone as a sealant on sailboats will always fail. Just look at any old boat that has had it applied and applied and applied.

Silicome is not impervious to water. As a mater of fact over time it will absorb moisture and seperate from the surfaces it was applied to.   In addition it contaminates the surface for any further work.

If you going to seal something seal it right. Pick a product designed for what you are doing. 

Life Caulk for bedding.  3M 4200 or 5200 for sealing and bonding. 
Note: Only use 3M 5200 if you never ever plan to take the item apart again. It will bond so well you will damage whatever your taking apart if it has been used.

sikoflex is the same as 3M  New skin on same old sausage.

[s/v Faith]

YES!!!
  Ok, I am a bit of a fanatic on this issue.  I have been know to all but tackle people walking down the docks with a 'Home Depot' bag, and a tube of silicone poking out.

____________________________________________

post on the Ariel site, when I had first been afflicted

Silicone.   



This is truly an evil evil thing. I removed all the hardware from the area surrounding the lazzerette hatch this afternoon. Sadly, it was not bedded in 4200, or even 5200. It was gooped in Silicone sealant.



I know I will have to remove it, and grind all of the gell coat off that has been in contact with it, and then hope for the best.



The reason for this post is simply to say, for anyone who may not know.



Do not ever use silicone sealant on any surface on your boat that will ever need to be painted!



It really does not stick well, and it wicks into the paint/gelcoat and makes it nearly impossible to get paint to stick to anyting in the future!



Thanks for listening. I may be better now

  I later had to remove more fiberglass after the paint would not stick to the places the silicone had sept into the glass.  Sanding does not remove it all, you have to grind or even chisel it out some times to get at it all!


  Here is a link to the thread.... Lots of good comments on the evils of silicone. [/b] [/color]

[Zen]

Grrrrrrrrrrrrrrrrr.
Ok, that ruins my temp plans. Ok, what is good for doing some temporary patching until one get the time to take the whole leaking mess apart to reseal it correctly.

I always thought Silicone was a good / convenent temp patch.

[s/v Faith]

Depends on what you are doing.

  If you are just looking for a general 'goop it on, I know this is not the right way, but I am gonna take it apart and fix it later' solution then....... Just don't do it.   






:)



No, just kidding, (but it is really easier to just do it right).  I carry a small tube of 4000 in case something like that came up.

[Zen]

 ???this 4000 is that another 3m product?

Well looks like I will need to change my recommendation for sealing stuff.  I just read the link on Silicone sounds bad. Glad I read it before I did any more damage , like this weekend when I had some projects in mind.

Ok, so I go to West Marine and I ask for ...?
some 4000 to stop a small leak around a port, until I take it apart an use Butyl to seal...?

And when I take the santions off to reset them and seal, I use ??

An for those little holes in the cabin where stuff was mounted inside the cabin...I use expoy or 5200?

And to seal the deadlight(?) why are they called that? I can also use 4000 until I replace them with screw on Lexan with a gasket of...?? Butyl ?

I knew that silicone did not last but I did not know it was damaging. I thought it was a good gasket/sealer.

First no Santa, now this...next duct tape will be a vilian. :'(

[Jack Tar]

For temp repair use one of the soft setting 3M products OR Sicoflex its the same thing. When filling an old screw hole DO NOT USE EPOXI. Sorry I got a little excited there. Sanding down pure epoxi is very very hard since the resin is pure. Be sure to make a mixture of Epoxy and Talc or micro balloons like the West Sytem uses. Make a paste like bondo.  Oh and yes you can use bondo.  This will alow you to sand it smooth without damaging ajacent surfaces. Then you can paint or touch up.

[mariner3302]

darn, s/v Faith! Gotta opinion?? lol Good info though. I have to get some sealing done on a hatch cover. i was actually thinking to lay a bead of 5200 around and let it completely cure.. then it should be a secondary seal. Maybe?
Ever get that heater in? Sure wish I had beat ya too it.

[s/v Faith]

....s/v Faith! Gotta opinion?? lol Good info though.....

  Yea, I got a little worked up, but this was after I had to destroy perfectly good fiberglass to get rid of the Silicone........


  Is that 5200 being used as a 'gasket'?  It sets up really hard, and will make it tough to get the hatch (frame?) loose if you ever need to replace/reair it.  What part of the hatch are you putting it on?

[Zen]

Ok, so I've trashed the Silicone And I picked up some 4200 as a replacement for doing stuff eg: leaking ports gasket, attaching carpet, leaking hatch, etc

Good? no good?

[s/v Faith]

 ;D

  Yes Zen, I think so.



  There is a fine line between 'Dear' and 'darn' in the acromyn DPO (darn Prior Owner) .

  Proper maintenance is a big part of the difference.... IMHO.

(I also had to use a CLAW HAMMER to remove the bondo that a DPO had used to repair the transom once....  ::)  Now, bondo was cheaper, and maybe easier to use (doubtful) then the proper epoxy based filler.  But the Bondo absorbed water through the paint and failed. 

Just like the cabin top on which the paint was peeling...... I found that there was no primer used..... and even found places where dirt was traped in the paint. 

I may well screw things up too, no one's perfect.  But at least I will screw it up trying to do a good job.... with the correct materials.
 

[starcrest]

sorry folks but my friend Margret (she prefeeeerrrrrs to be called "Margo") has found an excellent use for silicone.you know she was at one time a carpenters dream....but since she has had silicone implanted into her pontoons....well this has made her very bouyant indeed. she has also become very prominent in a crowd  ya just cant miss her..now she is the reason boats are preferred to as "she"...and "Margo" is a very important piece of equiptment,,,she performs a verrrrrry important function ....and I am very sure to always keep her well oiled indeed.........

[Zen]

Starcrest: you are the man as far as I am concerned. I purchased the boat I currently  have, partly on on your recommendation ( we have the same boat), but once in a while i go  ???
what is he talking bout ... :D

[captedteach]

OK folks 3M makes a product that removes sillycome - Its 3M Adhesive remover in a red and white can.  It may take a while for stuff thas eeked into gelcoat but DO NOT sand it as that just spreads it around and pushes it into the scratchmarks the sand paper is making.

Deadlites are plates that go over portholes to seal them during a storm incase some floatsome slams into the boat at the port level. They seal with a gasket and the pressure from the thumbscrews

Carpenters Dream - is a chik that is flat as a board and easy to screw, I'm guessing that this one got a really nice boobjob amd her sexual appetite is the same as it always was.  VIVA LA SILICONE!!!

[Coastal Cruiser]

Okay, let me stir the mix here. I use a common product that cost me around 4 bucks a tube and can be purchased at most all big box stores. Its a PL product, called Window, Door, Siding sealant, and works wonders, and yes it can be cut with a razor knife when removal time is required. Yes its got some adhesion properties, but not to great that you cannot work it out. It flexes, and in most cases, as long as the temperature is moderate, will cure in a day.

The only down side of it, it does take a week or so to properly cure for painting it. You may notice some form of dirt collection on a wide bead, is used, since it will cure but remain sticky a bit. But after the initial cure of it, mineral spirits will wipe most of the tackiness off. But for a good seal, and even improper fits with hatches to curve decks and hulls, it works great. Thats my opinion, of course and like freebies, worth to most exactly what was paid for it,  in most cases. Try it before you place in on a part, if skeptical of it, in you idle time while sitting around the puter, in spare junk we all have in our garages, or cabinets.

If you do not use it all, then just place a flat head, cheap screw driver in the end of it, one of those long ones that you find in the bins that stare you in the face at the checkout, that the tips also break off the second time you use it under load in the ends.  If you have cut the holes small enough, then you do not need anything to save it till your next required fix. If you wait to long and have to cut the tip off to use it, then a sharp razor knife will also remove the stuck leftover off the screwdriver for your next "corking" job.

[krissteyn]

Use-ing 5200/4200/sekoflex/or similar ,  as a seal...

I put the reqired "bead" in place and cover it with common kitchen shrink-wrap being carefull to leave no creases - close the hatch cover or similar without tightening excessively and let cure - remove shrink-wrap - and voila - a perfect seal . 

[psyche]

If you are trying to seal a piece of Laxan regular silicone, 4200, silkaflex is not the product to use. It will eventually leak because of the Laxan. It takes a special sealant. Especially if your are rebedding a port glass or hatch glass. The hatch companies including Bomar use GE UltraGlaze Structural Glacing sealant SSG4000. It is for bedding Laxan in port or hatch. It is very Black. It should not be used anywhere else to bed anything else. Yes it is a silicone! It was designed for just what I said to use it for. Bomar is one of the largest producers of hatches. This stuff is very difficult to find. It is not found at a building supply like Lowes or Home Depot. If you call 877-943-7325 or www.askgea.com or 866askgesa they will assist you in locating a supplier. You can also use the black goo that is used to seal auto windshields. I think that is what was used to seal my fixed side windows. If you are bedding deck hardware use 4200 and don't tighten it down until it sets.  Dan

[GordMay]

Although it might be tempting to use Silicone for temporary sealing jobs, this may be one of it's worst applications.
Silicone Sealants always leave an oily/waxy residue, to which nothing (including silicone) will stick.  These residues are extremely tenacious!  Deep abrasion is the only foolproof way to remove these residues, though some recommend cleaning with solvents, surfactants, or  proprietary silicone remover(s). 
FWIW,
Gord May

[US33155]

OK. point taken.  You guys hate silicone.  What about when the manufacturer recommends silicone, and actually indicates that other products like butyl caulks are NOT to be used? ???

[Coastal Cruiser]

We need to know the context of recommending silicone. Next, in almost all cases, when doing maintainance and upgrades some form of finish work is required, maybe not in your case, but silcone does not hold paints as a rule of thumb. Also in the issues of caulks on a boat, there needs to be some form of adhesion because of the moverment of parts, either by natural causes and elements and by the seaway motion that takes place in the "washing machine".

I would think that most do not like any adhesive caulks with the bad rap of knonw names as 5200, because of down the road of removal, which may or may not be an issue, even using the properly chosen adhesive caulkings or seleants.  But when water penetrates even 5200 parts, this is not an issue.



The makers of such caulks are evolving each year, providing a better and more user friendly product that is indeed a workable and favorable product that gives us both adhesion and and with some persuation, removal of the parts which has required the bonding between to different and mismatched surfaces.

[starcrest]

I hate to disappoint you  all but I have used silicone (standard hardware store issue 2 bux a tube) to seal  thru-hulls with fantastic results.