Fiberglass... Getting It Right

[scarlet]

I have watched dozens of videos showing how to make small repairs in fiberglass and or gelcoat, and not a single one looks good. In all of them I've seen, the finished holes are clearly visible, and look patched. What I want to know is how to fill and repair small holes so that they completely disappear. Is this impossible?

I have several spots on my boat that need attention. I'm removing a lot of "snaps" and "fasteners" from around my bench seating and windows... I have some dings where chips of gelcoat have come out... And, I have a larger repaired area that the previous owner did... it's smooth... dull... color is off, and is generally an eyesore. I haven't a clue where to begin on that area.

For the tiny screw holes, it looks like an epoxy would be the best bet... but how do I perfectly match the hull color and shine? (we have a 2011 Lagoon 450).

[Chotu]

Repainting (painting) large areas is the only way to get a perfectly unnoticeable color on the repair. This is because gel coat fades. You can't get a perfect factory gel coat color because that color is changing over the years.

Only paint will be perfect.

[Chotu]

Filling is easy. Grind each hole down a little so the hole is in a deep "dish" in the surface of the material. Put your thickened epoxy in the hole. Stuff it in good. Put more epoxy than you need so it's sticking up above the surface. Sand down the protruding epoxy for a perfect surface to paint.

[scarlet]

Originally Posted by Chotu

Filling is easy. Grind each hole down a little so the hole is in a deep "dish" in the surface of the material. Put your thickened epoxy in the hole. Stuff it in good. Put more epoxy than you need so it's sticking up above the surface. Sand down the protruding epoxy for a perfect surface to paint.

That is exactly what every video shows... So super easy. Just like repairing drywall... Perhaps it's the"paint" part that is missing? Because every video ends in them looking patched.

[undercutter]

Originally Posted by scarlet

That is exactly what every video shows... So super easy. Just like repairing drywall... Perhaps it's the"paint" part that is missing? Because every video ends in them looking patched.

Read post #2

[scarlet]

Originally Posted by Chotu

Repainting (painting) large areas is the only way to get a perfectly unnoticeable color on the repair. This is because gel coat fades. You can't get a perfect factory gel coat color because that color is changing over the years.

Only paint will be perfect.

Is there some place to get the color code for a particular boat?

[Chotu]

Originally Posted by scarlet

That is exactly what every video shows... So super easy. Just like repairing drywall... Perhaps it's the"paint" part that is missing? Because every video ends in them looking patched.

That is correct. Aside from sanding it enough that it is not a rough surface, paint is it. You cannot match gelcoat. You can try, but it’s never going to be perfect. Just re-paint the area that you are repairing. Repaint it from one end to the other. And you won’t be able to see the fixes.

[TrentePieds]

Quote: "Repaint it from one end to the other."

To expand on that a bit: A "panel" such as, say, the port side of the footwell in the cockpit extends from the "corner" that is the fore-edge of the seat down to the corner at the deck sole, and from the bulkhead forward to the bulkhead aft. If you paint this entire panel, the eye will, provided the colour match with surrounding areas is close, perceive the colour of the painted panel to be identical to that of the surrounding panels. It's the corners that fool the eye.

TP

[bcboomer]

Aren't there professionals who blend in new gelcoat?
IIRC there have been forum members who describe matching gelcoat well enough that they aren't visible.

[sailingchiro]

Decal?? Typically the snaps are in a straight line. Can you cover the blemishes with some type of pinstriping? As for the dock rash, I like a product made by 3m Scotchguard that is put on cars to prevent rock chips. If/when it gets messed up, just peel off and re-apply. It provides a good coverage of previous damage. I also like to cover the front of the bow. You can epoxy and touch up with paint. Sand smooth to 2000 grit then apply the rock guard. I like about 6" on the topsides.

Another way to blend is apply tape that is applied to area with half of the tape off to allow overspray or less spray to be applied. This doesn't produce a line then alot of wet sanding to 4000 grit then wax.
The idea is to blend from a larger area. Maybe 3-6" around the area and sand smooth.
I still like my scotchguard vinyl cover to the top of topside in order to cover previous blemishes.

[Squanderbucks]

Even when going to ultimately paint the surface a surface can only be made somewhat smooth and porous free using epoxy fillers and gelcoat. Typically once the decision is made that you want to paint the surface the process usually involves several coats of primers each sanded even more then two to 4 coats of topcoat to get the glass smooth finish desired.

But all of these processes involve spreading the repaired area out to the maximum you can tolerate. The physical repairs may be 12 X the size of the hole or defect as a general rule to allow "feathering out the finish".

Some finishes can be repaired better than others after the work is completed. Gelcoat is fairly repairable and can look nice (not perfect) if not too old. And requires hiring a an experienced gelcoater. AlwGrip is not considered a good surface for doing repairs to even though this is an excellent finish. Awlgrip does make some other finishes that are considered "repairable". Other brands vary and best to talk to boatyard people who work with the different products to get a feel for who works with what brands and their relative "patchability".
All boats get nicks and dings from time to time and require some patching. When they mount up enough to really bother you or become large enough to warrant the time/expense the total or at least large sections need to be repainted or gelcoated.

[Kelkara]

This guy seems to know what he's doing ... but he doesn't make it look easy.

https://www.youtube.com/watch?v=yoURRmkD8MY

https://www.youtube.com/watch?v=MxzCZ-5lMxY

https://www.youtube.com/watch?v=5MWN7kbzutM

[guyrj33]

Originally Posted by Chotu

Repainting (painting) large areas is the only way to get a perfectly unnoticeable color on the repair. This is because gel coat fades. You can't get a perfect factory gel coat color because that color is changing over the years.

Only paint will be perfect.

Buy color matched gel coat from a shop that provides the service and spray gel coat. Not really the hard and way better than paint.

[GregW1309]

I've never successfully matched gel coat by using dyes. I have matched gel coat using pre-colored gelcoat from: https://www.fibreglast.com/category/colorgelcoat. They have a color book you can rent or buy with 900 colors. I was able to match a salmon color hull, well weathered, such that you can't tell it was repaired. I used their thinning agent and sprayed it on with a preval sprayer (from Home depot). There are several video's that show how to do it over West System Epoxy, which I also used. Google "how to apply gel coat over west system epoxy".

[Nicholson58]

I fill small stuff with MarineTex white. Sand and fair. Paint is the only way to finish. I do my entire boat in the whitest white AwlGrip. Subsequent repairs are easy.