Windshield exterior sealant issue

[0TreeLemur]

A previous owner of our C put some kind of hard silicone sealant around the windows on the outside.  When we replaced the side windows in 2019 I removed a bunch of it.  It is firmer than regular silicone, and definitely not the polysulfide window sealant we used.  Now that sealant is failing around the windshield.  The picture shows the situation.   Any suggestions on what to use to fill the gaps?

Fred

[apriav]

That is ugly.......Might try some Chemseal 3204, it sticks everything.

Spruce has it.

 

[ArtVandelay]

Why not just use PRC you mentioned?

[jetdriven]

Pr1425.   But you got to remove that silicone stuff first.   Nothing sticks to that. 

[Prior owner]

Buy plastic razor blades on Amazon and get rid of it. Mask and apply correct sealant!

[N201MKTurbo]

This is what I use. Got a bunch compliments of AA.

https://bcwengineering.com/product/celcon-scraper-bcw-pn-45008-01/

 

[N201MKTurbo]

I would scrape it all off. I have found that IPA removes the silicone residue better than most things. I would loosen the screws around the window, then shoot some polysulfide in the gap and then re-tighten the screws.

[jetdriven]

IPA destroys plexiglas 

[Fly Boomer]

There is a $74 minimum order for bcwengineering.com and that's a lot of scrapers.

[N201MKTurbo]

26 minutes ago, jetdriven said:

IPA destroys plexiglas 

So does everything else that takes off silicone. I guess soap and water and elbow grease is going to be the answer.

[N201MKTurbo]

7 minutes ago, Fly Boomer said:

There is a $74 minimum order for bcwengineering.com and that's a lot of scrapers.

Sky Geek has them too, but I refuse to buy anything from them.

Just search for Celcon scrapers.

Edited January 17, 2022 by N201MKTurbo

[0TreeLemur]

11 hours ago, ArtVandelay said:

Why not just use PRC you mentioned?

 

Doing that right would require reinstalling the windshield, wouldn't it?   That's an A&P task.  Sadly, I don't have a local A&P that I would trust with that.

I'm going to get a Celcon scraper and see what it looks like after removing.

[201Steve]

31 minutes ago, 0TreeLemur said:

Doing that right would require reinstalling the windshield, wouldn't it?   That's an A&P task.  Sadly, I don't have a local A&P that I would trust with that.

I'm going to get a Celcon scraper and see what it looks like after removing.

PRC 1425A I believe is the correct exterior sealant. Would not involve removing wind screen. Just removing and replacing what sealant exists there. Lots of threads on here about it. 

[Sixstring2k]

15 hours ago, N201MKTurbo said:

This is what I use. Got a bunch compliments of AA.

https://bcwengineering.com/product/celcon-scraper-bcw-pn-45008-01/

 

Yes please use the scrapers and take your time. 

[EricJ]

There are all kinds of plastic or phenolic scrapers that would likely work fine.   Something like this is probably a good candidate, and there are lots of similar products linked with them:

https://www.amazon.com/Scrapers-Contoured-Scraping-Windshields-Application/dp/B07W5Z2CBQ

 

Edited January 18, 2022 by EricJ

[carusoam]

When choosing scrapers…

Make sure the hardness of the scraper is softer than the material being scraped….

When two materials collide… the harder material scratches the surface of the softer material…

There are a lot of brass scrapers meant for scraping stuff off of steal….

The selecting something stiff enough to do the job…

And pointy enough to reach into tight places….

 

PP thoughts only…

-a-

[Igor_U]

On 1/17/2022 at 5:20 PM, 0TreeLemur said:

Doing that right would require reinstalling the windshield, wouldn't it?   That's an A&P task.  Sadly, I don't have a local A&P that I would trust with that.

I'm going to get a Celcon scraper and see what it looks like after removing.

Not so fast.

FAR 43 allows pilot to perform preventive maintenance and one of th tasks is: 

1. Replacing side windows where that work does not interfere with the structure or any operating system such as controls, electrical equipment, etc.

 Not a difficult job to do, it just takes time and lot of holes to drill in a plexy, but I've done it some 15 years ago so my memory might be failing. 

[0TreeLemur]

4 hours ago, Igor_U said:

Not so fast.

FAR 43 allows pilot to perform preventive maintenance and one of th tasks is: 

1. Replacing side windows where that work does not interfere with the structure or any operating system such as controls, electrical equipment, etc.

 Not a difficult job to do, it just takes time and lot of holes to drill in a plexy, but I've done it some 15 years ago so my memory might be failing. 

Yes, I know.  We replaced the side and door windows ourselves in 2019.   Replacing the windshield is not considered preventative maintenance though.   Removing it to reseal is probably the same as replacement.

[Igor_U]

On 1/19/2022 at 7:22 PM, 0TreeLemur said:

Yes, I know.  We replaced the side and door windows ourselves in 2019.   Replacing the windshield is not considered preventative maintenance though.   Removing it to reseal is probably the same as replacement.

True.

I somehow missed that you are talking about windshield and not wide windows...

[0TreeLemur]

After considering my options, I realize now that my windshield needs re-installation using the correct sealant.   I've got a trip coming up Friday, so today I decided on a short term fix.  I masked off everything but the old sealant, which is gray, and wiped on a new coat of gray silicone using my finger dipped in soapy water.   I pressed it into the cracks in the old stuff as best as I could.  The gap shown in the photo I used at the start of this thread is now filled, as are the rest as far as I can tell.  Thanks to all for your input.

 

[BobbyH]

2 hours ago, 0TreeLemur said:

The gap shown in the photo I used at the start of this thread is now filled, as are the rest as far as I can tell.  Thanks to all for your input.

It's never easy to effectively seal the windshield but it looks like you did a great job.  Hopefully it will last for many years.