Exterior caulk?

[Star0210]

So we have some yucky cracked caulk on the exterior that needs to be replaced. We have already heard several opinions in what to go back with.
So what say you?
Is regular household exterior caulk good enough or.....something else?
Someone suggested 5200. Pretty sure we are not going to use that.

 

[Pack Mule]

I would probably use 3m 4000uv or 3m 3000uv. I would never use silicone on a boat. For rebedding hardware or window frames I would use butyl tape. Also look at some of the Total Boat products offered by Jamestown Distributors. Those guys are pretty helpful if you give them a call.

 

[jleonard]

I normally have used 5200

However, a lot of the construction/remodel guys around here in Florida are using this. Some of it has been in place for 3 years so far and it still looks good and is sealing.

https://www.amazon.com/gp/product/B00OIRRNVU/ref=ppx_yo_dt_b_asin_title_o02__o00_s00?ie=UTF8&psc=1

I've used it in a few places myself and it works very well. I plan on taking some north when we live on the boat for the summer as I have a couple of pesky leaks that need attention.
This stuff is pretty sticky, flows well and hasn't yellowed so I think it's worth a try.

 

[Lou_tribal]

If you want to get something that can stand a rocket fire and that will need you to use TNT to remove it go for 5200.
Joke apart what caulking? Where? Windows? Anything else? Your choice depends on your usage.

L

 

[RT Firefly]

Greetings,
Ms. S. I second Mr. PM's suggestion of 3M 4000 (never used 3000). Stays put and pliable and doesn't yellow.



5200?

 

[Comodave]

I only use 5200 below the waterline where I plan on never removing the item. I have been using Sika 295 (I believe). So far I really like it. In 2 years it has not turned yellow or given way.

 

[HopCar]

5200 should not be used where it is exposed to sunlight. It’s great for bedding a fitting but not if you need a bead of exposed caulk. UV causes it to break down.

 

[BruceK]

Sikaflex. 291 I think. But check the different varieties for the one which best suits. A tenacious adhesive as well as a sealant.

Not all silicones reject paint, some can be painted, and that some cannot is often the reason to reject them. But, Sika, and most polyurethanes, last longer.

 

[Lepke]

Some silicone products can't be easily painted over. If you run into that problem, the paint sold for covering stains usually works. Best if you sand first.
I know the marine products are expensive, but they were tested against the sun, wind and salt water to excel for a long time. Most house products aren't made with the ocean in mind and don't last as long. Even exterior products. The water based ones absorb moisture and are a magnet for mold.

 

[bluemainship]

5200 should not be used where it is exposed to sunlight. It’s great for bedding a fitting but not if you need a bead of exposed caulk. UV causes it to break down.

Are right,done made that mistake!

 

[Comodave]

In my previous post I said Sika 295, my bad, for general caulking I use Sika 291. I use Sika 295 when caulking plexiglass. I never use silicone caulk.

 

[Star0210]

I’ll tke some pics tomorrow of the different areas where the caulk is a mess.
I started scraping some today and found a place where the caulk was wet..sticky..left residue all over my hands. WTH?
All we can think is that the broker we bought the boat from said he had his guys re do some caulking before we bought it. I don’t know what it is or why it’s wet and sticky but it’s concerning.

 

[BruceK]

I...All we can think is that the broker we bought the boat from said he had his guys re do some caulking before we bought it. I don’t know what it is or why it’s wet and sticky but it’s concerning.

"Wet and sticky" is good in the right place, but not if it`s caulk, I`ve not seen that happen. Hope it`s not hiding something,get it cleaned out and replaced with polyurethane. Note Sika stays white,whereas another locally made polyurethane works as well but yellows with age.

 

[Comodave]

Yes, I used to use Boatlife Lifeseal, but it does yellow so I went to Sika 291.

 

[FF]

Calking only lasts for 6-10 years , then it will need replacement , best if done as PM, before the leaks start to rot the boat.

Dolphinite is probably the easiest to remove , clean off and replace.

Butyl tape is easy to replace , best when used on ports or hatches built to use it.


5200 is a glue and only for parts you are willing to damage to remove.

 

[Wxx3]

I found this link informative about Sikaflex products:
https://usa.sika.com/content/usa/industry/en/solutions_products/Adhesives/01b100/01b100sa02.html

 

[Westiculo]

I would probably use 3m 4000uv or 3m 3000uv. I would never use silicone on a boat. For rebedding hardware or window frames I would use butyl tape. Also look at some of the Total Boat products offered by Jamestown Distributors. Those guys are pretty helpful if you give them a call.

I agree - 3m 4000 is top notch.

 

[steelydon]

My experience with 3m 4200. I used this product to seal the pilot house glass on “Obsession”. This was a glass to aluminum seal and worked well for the first 2 years. Last fall I noticed it becoming soft and sticky in places on the front windows. I called 3m and they were less than helpful in assisting me in finding a cause or solution. The only thing used on the windows is windex and aquapel. Customer service said they only test their product against other 3m products. Not trashing 3m but removing/taping/applying new caulk is pretty darn labor intensive. I will definitely go with another product this spring. Just my $.02

Don

 

[Westiculo]

My experience with 3m 4200. I used this product to seal the pilot house glass on “Obsession”. This was a glass to aluminum seal and worked well for the first 2 years. Last fall I noticed it becoming soft and sticky in places on the front windows. I called 3m and they were less than helpful in assisting me in finding a cause or solution. The only thing used on the windows is windex and aquapel. Customer service said they only test their product against other 3m products. Not trashing 3m but removing/taping/applying new caulk is pretty darn labor intensive. I will definitely go with another product this spring. Just my $.02

Don

I know 3m 4200 is sensitive to some chemicals (teak cleaners for one) that can cause it to fail. 3M 4000 does not have these same problems. These are different products - 4200 is a polyurethane while 4000 is a polyether.

 

[Star0210]

This is where the wet caulk is.

 

[Star0210]

And just a few more pics of old yuck caulk that needs to be redone.

 

[RT Firefly]

Greetings,
Mr./Ms. S. Oh yuk! Given the "sheltered" location of the area that needs re-caulking, I'd be tempted to use a good non-silicon house caulk. Failing that, as others have said, 3M 4000.


Edit: Just saw your additional pictures. Yup, 3m 4000. Forget my suggestion of the house caulk...

 

[Westiculo]

This is where the wet caulk is.

Gross. That's 3M 4000?

 

[Larry M]

I’ve had poor results with 3M 4000 UV. It doesn't hold up in the tropics for us. The caulk in the picture is less than 3 years old. A bad batch? I’ve Googled 3M 4000 and stayed off of venders web sites and I see there are others with similar results. I’m still looking for something better.

 

[Star0210]

Gross. That's 3M 4000?

We have no idea what it is. I just found it the other day when I started scraping the old caulk. We’ve owned this boat for almost a year now. So this was put on before we bought the boat.

 

[Star0210]

Some silicone products can't be easily painted over. If you run into that problem, the paint sold for covering stains usually works. Best if you sand first.
I know the marine products are expensive, but they were tested against the sun, wind and salt water to excel for a long time. Most house products aren't made with the ocean in mind and don't last as long. Even exterior products. The water based ones absorb moisture and are a magnet for mold.

There is one caulk line that is molded. It drives me nuts every time I see it...which is all the time because it’s in a very visible location. It’s not cracked, just ugly because of the mold.

 

[Comodave]

I used to use 3M 4000. It turned yellow in less than 2 years. I started using Sika 291. No yellowing yet and it has been over 2 years.

 

[caltexflanc]

One trick pros use on 5200, 4200, Sikaflex291 and the like is to paint it, in the case of my old Hatteras, my guy used Awlgrip that matched the hull. Worked great and cut down mildew and ingrained dirt (which causes mildew).

 

[CEC]

The gooey stuff from underneath almost looks like putty or old white butyl its also what box store bathroom calk ends up looking like. Sikaflex 291 is what I would use once the old mess is cleaned up real well..

 

[Irish Rambler]

I agree with Bruce.
I've used Sikaflex for years and never had any problems. I definitely wouldn't use any household sealers, they definitely work but, indefinitely.