Removing windshield top sealant residue

[Joel Ashley]

So, I've had this ongoing issue with water getting into my electric bay following rainstorms.  BCS looked at it a couple of times and claims the questionable windshield sealant across the gasket top to the cap is fine.  It is the only obvious place water could be getting in, probably running down the cap inside and dripping in through a wiring porthole in the bay ceiling.  Why BCS can't see it like I can is beyond me.

I dressed the gaps up there a couple years ago with Lexel, and it stopped for awhile, but more of the old sealant has deteriorated since and the pond in the bay resumed this winter.  I used a razor to get some off but I need to remove the old sealant residue, silicone I presume, that is between the rubber brow and the cap.  I can say the part that was Lexel was tough stuff and is hard to get off the rubber.

Is it safe to use acetone to remove the residue from both the rubber and the cap, or is there a better solvent?  I'm gonna have fun trying to get the brow to lay back flat again, since its been bowed out and deformed in two spots for so long.  Hopefully fresh Lexel will hold it in place when cured and stop the bay intrusion.

Joel

  

[Karl Welhart]

Joel,

Do not use acetone... It will eat right through the paint and discolor the rubber molding.  I would use denatured alcohol or mineral spirits.  Getting the old silicone off is the key to getting a good seal.  I noticed your marker lights, they should also be checked for proper sealing and cracks in the lenses.

Karl

[Joel Ashley]

Thanks Karl;  I often use acetone on things, but thought it might be a bit strong for rubber and clear coat.  Just wondered what others have successfully used.  

I noticed microcracks in a few of my marker lights last year, after others on the Forum made mention of the issue.  I subsequently had BCS replace my markers exactly a year ago.  Why they weren't concerned about the windshield brow while they were up there (and I'd mentioned it for the third time since 2008 ), I don't know.  Plus last spring the tech got soaked when he found the defroster air tube between the firewall and front cap full of water.  They just keep telling me the windshield gasket brow is fine, but does it look fine in my photos?  They have always been reliable, so I didn't take their opinion lightly.  Still, water is getting in and that broken brow seal is just too obvious to me, so if the bay is still getting wet after I reseal it myself, then kudos to BCS I reckon.

Water isn't running inside the windshield, although I did find it had dripped on the dash from the overhead one time a few years ago, but I think it must be tracking along the gasket top edge and down the driver's side post on the inside of the cap, somewhere along the cap/sidewall junction and following a wire loom into the bay, since I've seen drops on the gray foam material used to fill the hole where the large loom comes in from above.  I've been going to remove the driver's left control panel to check behind it for staining.

Joel

[Edward Buker]

Joel,

You might try DX330 solvent wash from PPG available in auto paint supply houses. It will not take off paint or clearcoat. It may just be enough to help a bit and when you get enough of the sealant material off of the surfaces this solvent is a good surface prep chemical. West marine sells black thin plastic mixing sticks for working with thier West system of epoxy. I have used these before to scrape behind a gasket. They do not tend to damage paint but are stiff enough that they can act like a putty knife in this instance. Good tool for this job...

http://www.westmarine.com/webapp/wcs/stores/servlet/ProductDisplay?productId=15018&catalogId=10001&langId=-1&storeId=11151&storeNum=50218&subdeptNum=50219&classNum=50227

Later Ed

[Dave Cunningham]

Joel,

this is the tool I use for everything on the outside ( and sometimes inside ) on my motorhomes, it is a scraper made from a piece of 1/2'' plexiglass, , I have tried every store bought scraper that I could find and nothing works better than this, just cut an 8'' piece of plex to the width of your choice on the table saw ( triple chip blade works best ) use a disk sander to make a 45 degree bevel , and then round the corners on the handle end, these will take off anything without harming your paint, just sharpen once in a while with the disk or belt sander, I came up with these when trying to figure out how to remove the 3m front bra on my 2000 marquis, ( watch for the upcoming youtube video )

Dave

[Joel Ashley]

That sounds like a plan, Dave, assuming I can find 1/2" plexiglass somewhere around here.  

Was at Lowes today for yard sprinkler parts and was tempted by some caulk removal tools.  By the way, I discovered they carry Lexel in caulking gun size, though I didn't see any in the handy squeeze tube like Ace Hardware carries.  Was also pleased to discover our brand new local independent hardware store has the squeeze tube.

There is a West Marine about 20 miles from here, so not sure which is worse, the $10 shipping on a $3 set of epoxy mix sticks or the gas, Ed.  And I can't find yet an auto paint outlet for the DX 330.  Will check regular paint stores tomorrow, but noted our NAPA store has a 3M adhesive remover in its auto body section.  It's main solvent is xylene 330 (?) and I'm wondering if plain xylene or xylol would do the job?

Joel

[Edward Buker]

Joel,

The PPG DX 330 is a grease and wax remover painting preprep that does not harm paint, clearcoat, and I'm pretty sure rubber also. It does not evaporate immediatly so it has some work time. I'm sure that the auto paint supply house you have nearby will have an equivalent product in another line.

 In your case I do not believe that you will find something that dissolves what you have been trying to remove without harming the rest. I think you want a solvent with a little work time to help lube the interface you are working with some kind of stick/tool and help release the bond of the silicone or whatever. I think the plexiglass is a great idea but it may be too thick for where you have to work. If you thin it enough it may be too brittle, maybe not, you might find a sweet spot. Good to try both tools if you end up getting them and see what works. If you have success, let the rest of us know what worked. Good luck...

Later Ed

[Joel Ashley]

Thanks my friends for your input.  I wanted to put up the windshield cover since our unusually sunny weather began last week, and it cuts down tremendously on the heat getting in the coach through the south-facing windshield.  But as you can tell from the center fastener position in my photos, the cover will interfere with my repair, so I haven't put it up yet.  In fact I am suspicious that the cover may have expedited the problem as it traps heat where it lays over the brow up there?  Don't know, but the gasket problems did start after Monaco Harrisburg replaced the windshield in early 2007, and we got the cover the next August at the Redmond rally.

If I can't find the tools you recommend today, I'll put the cover up anyway.  Just been inundated with yard projects since this good weather began in the Northwest, and can't devote much drive time or work time to the coach and backed-up workbench jobs.  I've pried the brow out for cleaning, so now I have to get something done with it before rains begin again.

Gad, I thought retirement would give me leisure time!   ??)

Joel

Just located some DX330 in Oregon City, so headin' out.  Will ask if they have the expoxy mix sticks too, and maybe get a line on some 1/2" plexiglass.

[Dave Cunningham]

Joel,

You should be able to round up some plexiglas at any place that sells plastic and fibreglass supplies or a sign shop, we use thicker plexiglas all the time for push through copy on illuminated signs. You will love the way they work I just removed gobs of caulking from around my windshield a couple of weeks ago with the 1/2" wide version, if you need a bit more angle, just hit it with the sander and away you go, the scraper will remove all but the finest residue of whatever is on there , I usually clean the rest up with Goof Off, amazing stuff.

Dave

[Joel Ashley]

Okay, I've got the DX330, but there are no application instructions, just warnings, including one about not using it on fiberglass or plastic.  So I'm assuming it's okay if the fiberglass is painted over, since the concern seems to be about static buildup and flash fire.  

The auto paint supply shop also gave me a little red plastic razor blade, that fits in an old style window paint scraper.  It works to some degree, but there is a thin film against the cap fiberglass that is really stubborn.  I also picked up a caulking tool with a metal and a plastic scraper, and will see if the plastic side digs into that tough film.  I was hoping to soften the stuff so it would release and peel off instead of these micro shavings.  So far, no go.

Home Depot has plexiglass in quarter inch, and I almost bought a small sheet figuring to laminate up to 1/2", but didn't.  May call around tomorrow to places Dave suggested, and see if I can get 1/2" without driving 40 miles round trip.

By the way, they don't have Lexel yet, but our Oregon Wilco farm store has it in both squeeze tube and caulking gun size - they are a True Value outlet, so Ace is no longer the only place you can find it, and as I mentioned previously, I saw the caulking gun size at Lowe's.

Joel

[Joel Ashley]

Thanks to all who chimed in here.  Below is my arsenal.  I brushed on a disposable brush load of the DX330, let it sit a minute, then scraped along the film of old silicone at a steady angle with the red plastic part of the 3in1 tool I got at Home Depot.  The film peeled off the cap in strips like butter.  Any residual stuff I softened with more DX330 and wiped or scraped off easily.  The rubber brow on the other hand was more stubborn, and the old sealant got real sticky and gummy under the DX330 influence;  nevertheless it eventually came off with the help of the metal side of the 3 in 1 tool.  Then I cleaned the rubber brow and the cap with Simple Green.

Unfortunately my "beading" skills are limited, especially at the angle i was trying to work from -my stand-off ladder kinda in the way- and the Lexel isn't too forgiving on a warm day, so my reseal job isn't particularly pretty, but I think it will suffice.  The bigger problem is that the brow bows out, and I have few 10 foot devices to lean against it to hold it against the cap while the Lexel cures.  I can't seal the other side of the windshield until the first half is cured up and my ladder and poles and 2x4s are again available for holding the brow in place.  Rain for a couple days now, so reckon it'll have to wait til Tuesday to finish.

Once again, a hearty thanks to Ed for the DX330 clue... it works great.  And I'm still gonna find some 1/2" plexiglass for a set of Dave's scrapers.

Joel

The DX330 was about $13 and the tool $5.

[Joel Ashley]

Update:
It's been over two years since I worked on the windshield brow, and since Jim Crawford's recent post in a new thread reminded me of this old one, I thought I'd mention that I don't remember having to bail my electrical bay since.  Though the gasket probably warrants my getting up there and examining it again since it was in such bad shape before, at least I think my theory that it was the cause of my bay flooding is now vindicated.  I took out the sponge last spring that was to intercept drips before they got to the carpeted bay floor, because the sponge was never wet anymore.  Don't know that things will stay dry after we finally take the rig on the road for awhile, but at least I don't have to check the bay daily during rainy spells anymore, nor keep a dehydrator in there.

Again, thanks to Ed and others for their sage advice.

-Joel