sealing all screw holes

[mquiet]

Question. My surveyor told me to seal all the deck screw holes (windlass, Cleats, Rail bolts, Windshield, ect...) with new silicone. I know this sounds simple, but does he really mean to unthread every screw put some silicone in the hole and just re-thread the screw? Would the hole be a secure with the screw being backed out and then replaced? I would think that the fiberglass would not be able to handle it more than once? Thanks for the advice.

 

[skibum]

I can't tell you if you need to remove all of the screws or not. The trick to reinstalling screws in wood, metal, and fiberglass is to put the tip of the screw in the hole and turn it backwards until you feel the screw drop down a little. Sometimes you can even hear a slight "click" at the same time. After the screw drops, you can turn it forward and the screw will go into the existing threads. This prevents the screw from cutting a new set of threads, weakening the holding power.

 

[Quint4]

That is good advice. Do not use silicone, use 3M 4200. I spent an entire weekend rebedding every screw on my 290. The bow rail stanchions have bolts with backing plates and locking nuts as do the dock line cleats. This is an often neglected maintenance item that can be the ruin of a great boat. I say do this every 5 yrs or so.

 

[Jackie J V]

I love the tip on backing out the screw - thanks. One of those "whack-your-self-on-the-forehead-'Of course'-ideas"!:smt115

(plus I was just looking for an excuse for post #100 :grin

 

[sbw1]

4200 is good advice too.

 

[Spookeay]

Quint 4 has the right advice for this. The 4200 is the best on all through holes. You should Never Ever silicone to gel coat. Also, pull your windows and hatches and use rope caulk on them. Silicone to gel coat won't hold long at all. On the older boats, this was not understood like it is today.

 

[Lazy Daze]

Just as an alternative to 3M, you can use Boat Life's "Life Seal". I don't know if 4200 will, but Life Seal will cure while wet - in fact, they told me it will actually cure better than if it was dry.

My Sea Ray rep told me they predominantly use the Life Seal products. Probably doesn't mean anything more than that Boat Life and SR have a contract with each other, though.

Again, nothing wrong with the 4200 - it's great stuff. Just offering an alternative. I will say, though, that some of our older technicians (read as "lot's of experience":smt001) prefer the Boat Life stuff.

 

[SCORPIO]

Don't get any 4200 exposed to UV or it will yellow, be sparing with it and clean up any squash out prior to it curing. I found out the hard way on this once. There is supposed to be a new (4000 UV or something like that) that will not yellow exposed to UV. And don't use silicone.

 

[280 SeaRay]

If the sealant will be visible and exposed to the sun I like 4000 UV (which has been around for several years just much less common). Stays bright white even after years in the sun (personal experience). The strength and bonding characteristics seem to be similar between 4200 and 4000 UV.

http://multimedia.3m.com/mws/mediawebserver?66666UuZjcFSLXTtMXfXnXfXEVuQEcuZgVs6EVs6E666666--

Just like 4200 4000UV can be made into a perfect visible caulk line with a finger dipped in 90% rubbing alcohol. I rarely use 4200 anymore

 

[katricol]

What if some of the backing plates on the bow rail stanchions are NOT accessable??

 

[mquiet]

Thanks everyone. I have added 4000 or 4200 to the list.

 

[mquiet]

Agreed, how do I access the backing plates? I was hoping it would be a simple task of just un-screwing from the deck, then add 4000/4200 and replace. Yikes!!!!

 

[320Bob]

Along with sealing screw holes I am new to fiberglass as something to screw into. I would like to put some D Rings or the like to attach dog leashes to. Does one drill a pilot hole first and then set the screw or something else. I have set screws into wood, metal, plastic, dry wall, brick and masonry but never fiberglass so I needs some tips.

 

[mawyatt]

If the sealant will be visible and exposed to the sun I like 4000 UV (which has been around for several years just much less common). Stays bright white even after years in the sun (personal experience). The strength and bonding characteristics seem to be similar between 4200 and 4000 UV.

http://multimedia.3m.com/mws/mediawebserver?66666UuZjcFSLXTtMXfXnXfXEVuQEcuZgVs6EVs6E666666--

Just like 4200 4000UV can be made into a perfect visible caulk line with a finger dipped in 90% rubbing alcohol. I rarely use 4200 anymore

Is rubbing alcohol all that's needed to clean 4200 before it cures? Trying to make a mental note for when I use 4200 on my radar install.