Best Fairing & Filling Compounds for PMF?

[stepcut]

My hull is taking shape nicely,



But I really want to smooth it out before I layer it with PMF. What are some good fairing and filling compounds? Plain spackle? TB2 & foam dust? Something else?

I feel like spackle might be easy to work with -- but if it doesn't bond well to the foam and canvas, then it is going to be prone to delamination?

- jeremy

[tony.latham]

I'm a wood guy so I have no experience with fairing foam but you should take a gander through the pages of this build:

http://www.tnttt.com/viewtopic.php?f=55&t=48630&hilit=poet+creek

Bear in mind, it's still unfinished after six years.



Tony

[GPW]

J’, from our experience , the lightweight spackle isn’t so good as a filler ( doesn’t stick to foam that well, pulls away from the foam, stuck to the canvas skin ) … for cracks and holes the spray foam is effective … for surface irregularities , sanding usually does it , although we’ve been thinking about testing some Artists Acrylic modeling paste , which is foam compatible , sticks well,is flexible and you can sand it … Just a thought ...

[Tomterrific]

First let me say, I have no experience with this.

Shallow depressions (foam dents) might be dealt with by painting the foam area with high bond primer such as Gripper. The primer sticks to the foam and the filler (spackle) sticks to the primer.

Tt

[ghcoe]

I used the Light Weight Spackling throughout my #1 and #2 builds. I really have not noticed a sticking issue or a delamination issue, as of yet. I do sand and wipe down the foam with alcohol before applying though.

I also use Dap Latex Caulking to fill in gap. Usually at locations where there is a gap between foam pieces. I fill up the seam almost to the surface and then fill the rest with Light Weight Spackle to make it easy to fair out.

[GPW]

George we only noticed a problem when we took it apart for repairs … the lightweight spackling came off with the canvas … pulled away from the foam … But since we were using the beaded foam , this may be normal (?)
We went back with the spray foam , smoothed flat later with a sanding block ...

[ghcoe]

George we only noticed a problem when we took it apart for repairs … the lightweight spackling came off with the canvas … pulled away from the foam … But since we were using the beaded foam , this may be normal (?)
We went back with the spray foam , smoothed flat later with a sanding block ...

I have no doubt it would fail if you are pulling canvas off. The paint/TBII will bond better to the more porous material of the spackle and canvas and separate at the foam layer. But, if you notice the bond to everything else is quite good.