I wouldn't use it at all, you want the bond to be between the sealant and the gutter with nothing in between. I've seen it used lots of times and it doesn't help anyway if the gutter isn't fastened up properly.
Nope doesn't matter you can strip all the paint you want. Only thing is you might find certain types of sealant don't like to stick to bare aluminum. I know silicone doesn't, but also you should never use silicone for a gutter lol. I've really only ever used Tremco 830 so I don't know how other sealants do with the bare metal. One thing I can say for sure is that if you work on some really old gutters they are all bare aluminum on the inside and I've never seen anything other than silicone have a problem sticking to it.
Anything from acetone to gasoline can be used to to clean the surface but lacquer thinner is not corrosive to things like shingles, and has no effect on you other than to dry your skin out a bit if you use it alot. The main purpose is to clean the surface of dirt and contaminants and also helps break down any of the old gunk that's still left clinging to the inside of the gutter. I would think acetone would work just great.
Awesome. Thank you for your explanation!
What are your thoughts on using a fiber mesh tape on top of that, then applying another later of caulk/sealer to saturate and lock the tape in?
I wouldn't use it at all, you want the bond to be between the sealant and the gutter with nothing in between. I've seen it used lots of times and it doesn't help anyway if the gutter isn't fastened up properly.
Do you recommend avoiding stripping the paint off and going down to bare metal?
Nope doesn't matter you can strip all the paint you want. Only thing is you might find certain types of sealant don't like to stick to bare aluminum. I know silicone doesn't, but also you should never use silicone for a gutter lol. I've really only ever used Tremco 830 so I don't know how other sealants do with the bare metal. One thing I can say for sure is that if you work on some really old gutters they are all bare aluminum on the inside and I've never seen anything other than silicone have a problem sticking to it.
Could acetone be used as a cleaning/stripping agent, too?
Anything from acetone to gasoline can be used to to clean the surface but lacquer thinner is not corrosive to things like shingles, and has no effect on you other than to dry your skin out a bit if you use it alot. The main purpose is to clean the surface of dirt and contaminants and also helps break down any of the old gunk that's still left clinging to the inside of the gutter. I would think acetone would work just great.
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