Gelcoat Repair filler or Flowcoat for minor repairs?

[quobbarockhopper]

I have a few stone chips/ minor scratches as well as some wear marks/ indents where from the keel rollers (they have developed over time through travel/ pressure on the same spot when its on the trailer) on the hull of my boat that Id like to fix

Ive been doing some reading on whats the best stuff to use- flowcoat or a gelcoat repair filler and Im getting mixed info that I was hoping someone could help clear up through actual experience with them:

- Gelcoat repair filler: I got recommended a product called Septone Gelcoat repair filler, so ordered some of that. It appears easier to use that flowcoat as it sticky/ more workable- less liquidy than flowcoat When it arrived, the label says “not for use below the waterline unless the top is coated with a waterproof finish” although other people have said they use it on the hull with no problems. After some googling, it seems like older tins of this stuff didn’t have this warning on them- so either it’s a result of ass covering by the company or they have recently changed the recipe? Im thinking this might be meant for boats that stay in the water, but it might be OK for trailer boats when they are only in the water for 48 hours or so max etc. it’s a polyester resin Kit as opposed to a epoxy. Google again says that this may end in a tacky surface…

- Flowcoat: Again, google says that flowcoat is basically gelcoat with a wax mix to make it cure better/ non tacky etc. Bit more painful to use on the hull (vertical/ angled surface) from past experience as its runny.

That’s the background of where Im at basically. I guess the questions are:
1) Is the Septone Gelcoat repair filler OK to use on a trailer boat for below the water line?


2) Will the Septone or the flowcoat produce a harder/ better wearing finish (especially on the roller weat patches on the keel?


3) Overall, should I be using flowcoat or the gelcoat filler? (the bits Im repairing aren’t bad damage- stone chips, small scratches and then the roller wear which is a bit bigger)
Im obviously leaning towards the flowcoat option, just wanted some additional info, especially if one will give a harder/ better wearing result that the other, on the above if anyones had any direct experience- the internets throwing up a fair bit of conflicting information


Cheers in advance

[Dignity]

If deep scratches you could use the gelcoat repair first followed by the flowcoat. You will need to clean both surfaces before use other wise it'll fall out. Upside down chips aren't that hard, I usually tape a piece of plastic to the hull fill in the chip then tape the other side of the plastic, stops most runs. In the old days some guys used talc powder to thicken the resin although QCELL is the correct stuff, I have heaps of it if your interested, where are you located.

[EdBerg]

Gelcoat and flowcoat are basically the same but the flowcoat has wax in styrene added to stop the stickiness. When gelcoat cures, the surface is affected by the moisture in the air and so there is a very thin layer that does not cure properly. So when applied to a mold the surface make a good bond to the following layers of resin and glass. However it is also a pain to sand hence the need to clean it down (acetone) before sanding otherwise it gums up the sanding paper.

The wax in the flowcoat floats to the surface before it cures and stops the moisture from affecting the cure so you can sand it with out problems. When I used to repair boats I used to use gelcoat for small dents but used to cover the patch with sticky tape which did the same thing as the wax in flowcoat. If the patch was too big for the tape to cover, then flowcoat was used, but you have to make sure that you sand every bit of the flowcoats surface to remove the wax as a subsequent build up layer of gelcoat/flowcoat won't bond properly to any surface that hasn't had the wax removed.

Using the tape helps to reduce the amount of sanding required as well.