Zinnser Watertite Paint

For those who haven't use the Zinnser Watertite paint as a canvas filler, good. DON'T!

Think about this: It's got concrete in it. Concrete. Heavy, and NOT FLEXIBLE. To put this stuff on canvas, on a cedar, both of which flex, is not right.

Why am I postinging this? I just finished sanding down a layer of the product, on canvas, on a cedar canoe, and when done, I found cracks all over the finish! Of course the paint doesn't flex when it's dried, it's not designed to. Anything that's going to move beneath the cement like paint is going to cause the cement like paint to crack.

Nothing's going to fix the cracks now except new canvas.

I post this to hopefully save someone else the cost, time, and pain of having a good job ruined.

 

Hi Peter,

My canoe has had it for ten years and looks new. I have no problem using the stuff, but if something bad does happen I understand that I'll have to fix it. Zinsser sells a wide variety of sealer paints, maybe the one you experienced was some other type or you had another issue altogether? It does have portland cement in it which is the equivalent of silica or some other filler. concrete is not quite the same as cement. Also i think the waterproof paint may be different than watertite basement sealer. and if you think about it, the traditional filler material is lead and it's heavy.

I believe the tried and true methods and materials are tried and true for a reason. but, I also think that over the years canoe builders were always experimenting with different materials and methods, especially in the area of canvas filler.

Was your experience on a new canvas job? Or an older canoe? sometimes filler can crack as it dries and the finished product is no worse for wear. I'm not the Zinsser expert or have any stock in the company but feel free to PM me. Maybe there is something else going on? Check the label, I think the label says flexible but I am not sure.

And don't rule out concrete canoes. they race those things and I saw one for sale on ebay last week. Or was it Craig's list?
regards, Dave.

 

Technically speaking, "concrete is a construction material composed of cement (commonly Portland cement) as well as other cementitious materials..." and "in the most general sense of the word, a cement is a binder, a substance which sets and hardens independently, and can bind other materials together..." Thank goodness for Wikipedia!

I'm not a chemist but my first though concerning the cracking is that something other than the product itself is likely the problem.

Looking at the list of ingredients for both Zinsser (I finally found some BTW)and traditional filler there is a large measure of similarity. The portions might be different but they both have an oil base, a drier and a filler to add body. Oil based products generally have a degree of flexability to them even if they are cemented together into concrete.

I've seen checking in oil based varnish which was applied in a excessively hot shop and the varnish has dried too fast before it could properly vent. I've also seen it the other way also where the shop cooled too fast (winter time)and the varnish cracked. Mind you this was on musical instruments which are made from wood half the thickness of canoes and before I wised up and got proper heating in my shop but...and yes it was a PITA to redo the varnish.

I'm sorry you had this experience Peter. I hope you look into all possibilities and remember Sherlock Holmes observed that "once you have eliminated the impossible, then whatever remains, however improbable, must be the answer."

 

Hi Peter How thick did you apply the filler? Sometimes applying it too thick can cause cracking. Just another possibility. Bill

 

fuel for the fire

Largely for Mike Cav, but also for Dan"I love stitch and glue"Miller too i guess....

 

Hey!! Watch that! Dan is the epoxy fan!

 

sorry, forgot to mention she likes Guinness

 

Oh... well..., I guess that's a different story