CONTINUOUSWAVE

Q1: What are these small brown liquid deposits?



Some very tiny deposits are surfacing under new gel coat. I have no recollection of any preexisting damage or repair at this spot. There is a tiny pin hole under each deposit. The liquid feels like a foam styrene goo of some sort.

I can clean them up, but they reappear the next day.

Please clarify what is meant by the expression "new gel coat."

Q2: Did you recently apply new polyester gel coat resin to the hull?

Q3: If so, what was the surface that the new polyester gel coat resin was applied to?

Q4: How was the surface prepared?

Typically, brown goo is uncured resin. It is typical on Boston Whaler boats that are quite old to still have some uncured resin still in the hull, even on boats made 30-years ago.

Q5: How old is the hull?

To me that looks like moisture that is under the gelcoat, probably moisture from dew, humidity and rain that got sucks up through the pin holes and cracks in the gelcoat. The change in temps through the days and night helps suck the moisture up in there.

Once in there it breaks down the resins and comes out in form of brown vinegar smelling ooze. If it is smells like vinegar then that is what it is. It is not structurally bad but just looks back.

I agree with Jim, uncured resin escaping.

To test the theory of resin mixing with water, take some uncured resin and mix with water. Wait a few days and report what happens.

If that is new gelcoat then, I think it is uncured gelcoat too. You may want to do a small gelcoat repair on that area. But if left alone I don't think it will hurt anything either.

You could try putting a little heat on it to help it cure underneath. Polyester resin likes heat to cure and even uncastilized resin will cure over time on its own left alone.

Sorry for the delay in responding. Yes this is new gel coat over old gel coat that was sanded down.
It does seem to be more active if the hull is in the sun vs in the shop. In fact I never noticed it until I rolled the hull outside for few days. It's an 1963, 13 foot classic. I'll be doing a few small gel coat patches due to over sanding the new gel coat down to the glass. THANKS !

Bayou Bum wrote:Sorry for the delay in responding. Yes this is new gel coat over old gel coat that was sanded down.
It does seem to be more active if the hull is in the sun vs in the shop. In fact I never noticed it until I rolled the hull outside for few days. It's an 1963, 13 foot classic. I'll be doing a few small gel coat patches due to over sanding the new gel coat down to the glass. THANKS !

Is it the FGCI brushable gelcoat? If so, how was your experience with it? Have you tried sanding/compounding/polishing yet?

I used Total Boat products. I ended up spraying the gel coat and it tuned out fine, except I had a pretty rough orange peel. The gel coat sanded down to a beautiful finish, but, the sides of the hull were and are not perfectly smooth and the result is a very uneven shine. Some spots are super shiny, others still have some orange peel. Not the products fault, but I may now go ahead and paint the gel coat if I can find a topside paint that can take a week of being in the water. I have several thin spots where the new gel coat has been sanded down to the original gel coat or filler so I need to do something.

I'd go with a bright white high gloss bottom paint--if such a thing existed--and maybe even an epoxy paint. I am pondering my options.

All feedback much appreciated.

Just respray those areas as gelcoat usually blends in well if using the same color/brand. What caused the orange peel and would you be better off brushing it on?

I'm sorry if I sound highly critical of your workmanship with regard to spraying gelcoat. I mean no personal offence only technical advice.

Based on the one photo the gelcoat that has been applied is very bumpy. That indicates to me that it was not applied properly. A final gelcoat finish via spray application technique should not be even minimally orange peeled. The reason for this is a gelcoat finish applied topically as a refinish topcoat will need final wet sanding and buffing out. The more irregular the surface to be wet sanded smooth the more irregular the gelcoat finish depth will be due to the need of sanding off the high bumps. All finishes; paint, gelcoat or varnish; need to have a certain millage of finish depth for visual acceptability and specified use durability.

As to the bubbling of stuff from the gelcoat you applied. I do not disagree that it is uncured resin from the gelcoat finish you applied as long as your statement about the surface area you applied it to had no prior repairs etc- just plain old existing fiberglass/original well sanded gelcoat is accurate.

If the gelcoat is emitting unfinished resin during the curing process after application that is not normal at all. It either means the gelcoat was not mixed properly prior to application or the product is defective. Once gelcoat is mixed and sprayed properly you will not have unfinished clear resin bubbling from the finish at all. It has been a very short period of time between the application of the gelcoat and you reporting the finish bubbling. It's still in the curing stage.

Rich

I have also spent a bit of time thinking about the ability of leaving my project boat in the water for short and long period durations. A week of putting it in the water here and there, no bottom paint. 100% trailer stored but the ability to put it at a dock for a week or two and enjoy.

I would not hesitate leaving a boat in the water without bottom paint depending on local fouling conditions for a week or so if it is a boat that has original factory gelcoat that is in excellent condition.

I do not believe that a new boat manufacturer offers a gelcoat warranty that includes a no bottom prep clause if only in the water for "x" number of days.

I am going to barrier coat and paint the bottom with a hard bottom paint.

You asked if a white bottom paint is available. Yes they are.

https://www.jamestowndistributors.com/u ... o?pid=1438

Interlux Paint has an excellent product and application guide available on their website. Use their product or not they offer excellent easily accessible knowledge on paint finishing.

Rich