I guess I didn’t put enough catalyst into the resin/cabosil mix and now it’s the next day and the resin is still sticky. What to do? Sand it down in its sticky form and put another coat on top or dig it completely out and start over? I know I should measure catalyst more closely but when the cabosil gets mixed in I’m never quite sure what the ratio should be. Any help would be appreciated.
Try hotcoating the filler with some hot sanding resin.
If you can dig it out, then do so. Otherwise you can hotcoat it and sand it to shape and then glass it.
Watch those ratios!
Since I’m a cheap old fart, I used to wrap the sticky, gelled but uncured resin in wax paper, and wait one day.
Wax cures the surface so you can go on gumming up your sandpaper taking it down.
Like the gents before me said-
With filler powder or additives of any kind ( pigment, tints, etc) - they slow the resin down, as do cooler temps, thin layers ( glosses or thin/light cloth) humidity and dark. And they add together, so that a tinted or pigmented filler will be slower than tinted resin or resin with filler alone.
Thick layers ( ding filling, for instance ) , sunlight and high temps speed it up. In some cases, speed it up a whole lot.
What I do, and it may work well for you, is this -
I’ll generally catalyse on the low and slow side under cover. If I need to speed it up, move it out into the sun for a bit. By the same token, if I think things are going along a little too fast I try to have shade available so that I can slow it down and catalyse on the low side on hot days.
Leaving your catalyst in the sun, or old catalyst in general- I suggest doing a test batch with a few drops of catalyst to some straight resin, just to see if it works at all.
hope that’s of use
Thanks everyone! Swaylocks to the rescue…as always.
Howzit Lee, Now that's an old but true trick I think a lot of us older guys used because we didn't have access to S.A. or sanding resin. Recently I used it on a repair that had a lot of black on the deck and the wax didn't rise so I put the wax paper over the bad spots and put the board in the sun and the wax melted and the resin absorbed it to make a sandable surface. Wax paper is always in my shop. Aloha,kokua
Yep, wax paper is a lovely thing, also makes quick and dirty molds, parting compound between resin and stuff you don’t want stuck to it, all sorts of stuff.
There is, or was, a brand of ‘cling type’ food wrap that would also work and wasn’t soluble in styrenes, though I will be (expurgated ) if I can remember which one it was. Quite handy, you could wad in the filler and then put the film to it, it’d deform nicely and come very close to the shape you wanted it to be so very little sanding needed-