Glazing compound kicking too fast!

[L124C]

Just painted the Port side of my hull, and used 3M Acryl-Blue Glazing Compound to fill scratches. The instructions said it drys in 25 minutes at 72 degrees, and that you could fair entire panels with it if needed. I was applying it outdoors on a 70 degree sunny day with almost no wind. It kicked almost instantly. I could spread it once, maybe twice, but if I brought the spreader through it a third time, it turned into a mess. There is no way I could have faired a large surface with it. I'm thinking that it's formulated for shop conditions, and that because I was in the sun and there was a little breeze, it kicked too fast. I'm going to try the red compound which calls for dying overnight. I'll bet it will be more user friendly for outdoor use, and that I can sand it within hours under the same conditions. Thoughts?

[garyguss]

Dying overnite is kind of overkill

[tommays]

I used systemthree and was pretty happy but you do not get a whole lot chances at spreading it

The problem with any filler is what your putting on top of its compatibility and HOW long well the filler is going to handle hull flexing and dock bumps and stay on the hull

[Capt Len]

I don't do much plastic but i bet cool and shade would help on smaller areas at a time.Once the base has heated ,poof !

[SloopJonB]

Originally Posted by L124C

Just painted the Port side of my hull, and used 3M Acryl-Blue Glazing Compound to fill scratches. The instructions said it drys in 25 minutes at 72 degrees, and that you could fair entire panels with it if needed. I was applying it outdoors on a 70 degree sunny day with almost no wind. It kicked almost instantly. I could spread it once, maybe twice, but if I brought the spreader through it a third time, it turned into a mess. There is no way I could have faired a large surface with it. I'm thinking that it's formulated for shop conditions, and that because I was in the sun and there was a little breeze, it kicked too fast. I'm going to try the red compound which calls for dying overnight. I'll bet it will be more user friendly for outdoor use, and that I can sand it within hours under the same conditions. Thoughts?

Glazing compounds are intended to fill scratches and pinholes that are just a bit too much for high build primer to fix. You can't "sculpt" them in ANY way. One quick wipe of the spreader should be all that is needed or you are overusing them. It sounds like you should be using a more "bulk" filler like epoxy and talc or balloons.

If you overuse the glaze fillers they will not stay in place later - whatever you are filling will crack or loosen up under the finish. After sanding them you should only have the faintest traces of them left - little speckles and hazes of colour. Any more than that and it is too thick.

[JedNeck]

Also if your outside in the sun the surface temp of the hull is probably well above the 70 degree ambient.

[L124C]

Originally Posted by SloopJonB

Glazing compounds are intended to fill scratches and pinholes that are just a bit too much for high build primer to fix. You can't "sculpt" them in ANY way. One quick wipe of the spreader should be all that is needed or you are overusing them. It sounds like you should be using a more "bulk" filler like epoxy and talc or balloons.

If you overuse the glaze fillers they will not stay in place later - whatever you are filling will crack or loosen up under the finish. After sanding them you should only have the faintest traces of them left - little speckles and hazes of colour. Any more than that and it is too thick.

I was filling hairline cracks as you describe. No "sculpting" was involved (I have two part fairing compound for that). The problem was in covering a wide area. The material I had just applied had already kicked and would peel off as I applied new material to an adjacent area. I overcame this by doing spots and allowing them to cure fully before doing the adjacent area. If I had 30 seconds of working time, I could have quickly covered larger areas. I could have never faired an entire panel in one shot as described in the directions (and didn't need to), so I suspected the product was not performing as intended, probably due to conditions. I was not using it in direct sunlight, and don't think the surface temperature was above 70. I'll try the red and report back. I'll also report if it all falls off the first time I bump a dock! The funny thing is... I originally had the red (which is less expensive) and thought I couldn't wait overnight for it to cure!

[mike dryver]

cut back on the catalyst a little to give yourself more working time. working direct sun will heat hull as posted earlier.

[SloopJonB]

Originally Posted by mike dryver

cut back on the catalyst a little to give yourself more working time. working direct sun will heat hull as posted earlier.

Glaze fillers come in a tube and are not two part in my experience, they are lacquer based.