3m 5200

I am going to be replacing some bad rivets with stainless steel screws and washers. My concern is should the area around rivet hole be primed with self etching primer , or bare aluminum where I'm going to apply 5200? Or does it really make a difference ?

My 5200 job didn't last more than 5 outings before most of it was gone from pulling it up on sand bars, running through weeds, etc. I applied it on bare aluminum that I roughed up then cleaned with heat and then solvent before application.

I would use self etch primer. I assume you are putting the 5200 under the head of the screw? It shouldn't wash out, if you let it fully cure, takes about 1 week.

Yes I will be putting it under her of screw as well as on the inside of boat

Johnny from FL posted some pictures of an aluminum plate bonded to a hull with just 5200 on it, where the aluminum pieces weren't primed. There were corrosion spots all over between the 2 pieces.

IIRC he also showed another place that was bonded too, but the 2 pieces were coated in zinc-chromate primer first ... and they had no corrosion.

Ok thanks guys

Like Dale says - - - anytime you do do anything with aluminum,
prime it properly prior to proceeding to the next steps.

of course rivets and fasteners are much smaller and may or may not
produce the same corrosion factors as larger surface areas such as
transducers, etc.
Look carefully at the package when you buy the 5200. Fast cure will
set up quickly and cure in 24 hours . . . slow cure sets up in several hours
and cures in 7 days . . . SEVEN DAYS !!
so, read, understand and follow the instructions on anything you use.
only takes a few minutes to do it properly the first time.

jus my Dos Centavos




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Johnny said:

... anytime you do do anything with aluminum, prime it properly prior to proceeding to the next steps.

Click to expand...

WOW Johnny ... that picture is even more telling than I remembered it to be! I am like so saving a copy of that photo ...

You should write i as a post and have Jim save it as a stickie!