Silicone windsheild trim?

What's the general consensus on running a thin bead of clear silicone along the aluminum channel at the windsheild base? I've got a feeling this is an area that some water gets in. I can't see where it would hurt but I'm may be overlooking some obvious "no no".

Mickey--I am very interested in responses you receive to this post.. Do you get water in at the base of the windshield post too? That seems to be where most of mine comes in. ---Jack

Yes!
I run a piece of tape horizontal along the windshield trim base, then another 1/8" apart from the first piece on the cowl,
run a narrow bead of clear silicone caulk (you don't need much)
then a quick smoothing out with your finger and pull off the tape...done ! ~Alan

Edit: If you are getting water in at the post bases, just glob some silicone up under the dash around the post bolt and spacer ...done !

Excellent. Thanks Alan.

I ran clear silicon along the intersection of the lower windshield trim and the body. Somehow, it has discolored from what I presume is rust under the trim (the trim was screwed on with sheet metal screws which have rusted) so that it is now becoming a dark rust color in places.

I'm about ready to clean it all out of there and either leave it as is or run another bead - but I assume that the new stuff would discolor, too, right?

Always something.....

I realy can't say, I never seem to own the same speedster long enough.... ~Alan

How well we know.... :>)

Being an old bldg. trades sheet metal worker responsible for long term roof and flashing leak prevention, I would never use silicone. Look for a silver colored flashing or gutter caulk which is available at the home improvement big box stores if want to seal it from above.
I fixed my VS by laying on my back to caulk the attachments (pop rivets) with polyurethane from the underside.
IMH(professional)O, silicone is very well marketed CRAP.

I love silicone. Prefer natural but love silicone. RTV comes in clear,black,white and gray colors--great stuff!!

I ran the clear silicone at the base of the windshield trim and it lasted for years w/no discoloration. the only problem iI had was getting wax build up along the silicone edge. but was able to clean it up with a tooth brush - more work.

why not use a automotve product from 3 M like stip caulking put that in there nice 1/8 strips I have used it for years under all kinds of trim .

I'm no pro but I'd agree with Ernie, I'd stay away from silicone. I know when I had a windshield replaced a while ago the shop used some sort of black goop. I asked them if it was silicone and they said no way would they use silicone. I bought a tube of the goop from the shop and used it when I put the front and rear glass in my 912 coupe and it worked like a charm.

I was thinking that maybe plumbers putty might work well? Its cheap, easy to remove if you want to and its made to seal against water.

I will admit to using silicne for many things and always keep a tube in the garage.

Ernie - what is it that you do not like about silicone? What causes you problems? I have a feeling this is a time and sunshine issue?

Brian - I agree, you probably don't want to use silicone for windshield replacement. I know they have special adhesives just for that.

The windshield goo is just that--windshield goo, that is it's specific purpose. It kind of makes a bed to ploop into. Silicone has it's place also, it doesn't have the same "bedding" properties but seals just fine.
We use it on aircraft windshields and the temps range from +120f to -120f and all types of weather conditions-I like it.

Bruce,

Which is it that you use, silicone or goo?

Dave..
"what is it that you do not like about silicone? What causes you problems? I have a feeling this is a time and sunshine issue?"

The deal is that when a 80 story bldg. is erected, do you think that the developer would want to pay for leak failure on a window at the 65th floor a year after the bldg. is occupied? Sound costly? DOH!
This is why architects always specify polyurethane caulk at all weather critical connections. Glazers, iron workers, roofers, etc would NEVER EVER use silicone.
"Silicone" was the GE patented name for a NASA product that has great heat resistance characteristics. It CAN NOT withstand the force of the sun's powerful UV rays or the expansion and contractions between different materials. Also, paint will not adhere to it.
While it sells very well at the "big box" stores, over time if exposed to the elements, it will fail.
This means that if you keep your car in the garage and don't drive it too often.... it will perform to that standard pretty well, I guess.
Cheers, Ernie

Well, that settles it.....

Pearl stays in the garage.

Thanks for the info, Ernie!

;>)

Any RTV which produces acetic acid in teh cure cycle will corrode metal and is not a good choice for use in cars or on electronic assemblies. Almost all Silicone caulks and tubes of Silicone goo are of the acetic cure nature. If in doubt, squeeze some out and smell it to get that whiff of vinegar. What you want to look for is natural cure, acetone cure (not for plastics!), or something rated for electronics use.

Tomm

and it cures under water

When you finally decide on which product to use try to find one with a thinner initial viscosity and use a syringe with a large bore needle for the application. You can get into all those hard to reach places which might otherwise result in a mess and/or continued leak.

That's it, I'll just blue tarp the thing :)

I'm gonna take one of those things that people use for shade at car shows and bolt it to the car. Viola! Mobile auto umbrella!

Why do I have an image of a motorized hang-glider in my head...?

Well, um, yeah... There might be a few kinks to work out.

I saw in my CMC manual tonight that they say to use 3M 08551 on the lip of the lower extrusion.

Extrusion--what is that?---Jack

The aluminum piece fastened to the body at the base of the windshield.

3M makes pretty good stuff....
3M gutter and lap sealant is a great product (IMHO), when sealing ran gutters on a residential application. However, you may have a little problem finding it unless you go to a sheet metal industry supply house.
I considered using it in a nice bead where the alum meets the glass because it does come in a nice silver color. Dr Clock describes a good method above with the masking tape.
On closer inspection from underneath, I found that VS had not sealed the rivets in any way, so I attacked the problem from below. I globbed the polyurethane on rivets stubs underneath where it can not be seen by the public with good results. NO leaks.

"Do you get water in at the base of the windshield post"
Jack... That is a sure thing leak! If you craw underneath, you can actually see daylight through there. I fixed mine with an automotive windshield sealant that will match the rubber.
..... Just got in from Hawaii (why I'm up so late). I'll get back to ya on the product's name soon!
Ernie

I ran the vinyl on top of the dash under the windshield posts to act as a gasket.

Mike--how dd you get the sealer under the post? Did it come with a tiny applicator like a tube of caulk?

Ernie--yes, please do share the name of that product.

I want to do some windshield sealing before the Carlisle trip--although it will definitely be warm and sunny the whole time---won't it?---Jack

Jack,

I didn't put any sealer under the post. When I put the vinyl upholstery material on top of the dash I extended it under the posts.

My windshield is off again now to replace the corroded posts. Maybe I will put some kind of sealer under the posts now.

Why not get a genuine windshield post rubber gasket from some place like International Mercantile??

Phone: 1-800-356-0012
Fax: (760) 438-1428
email: internationalmercantile@hotmail.com

Part number M72 (644.541.261.40)

Price: standard: $3.00 per pair

(molded version) $15.00 per pair

Tell them it's for a Speedster (they have roadster and "D" styles, too.)

I'll second that. Their prices are quite reasonable, and they get it to you quickly - often in 2-3 days. They don't have a website to speak of, so you should ask for a catalog. Their number is 1-800-356-0012.

I did buy post gaskets from Klasse 356 for the post replacememt. They are narrow strips that fit under the edge of the posts.