caulking info

[keith c]

The prior owner, because of his dog ,placed canvas type barricades at the top of the flybridge stairs and on the port and starboard walk ways in an area leading to the bow. Because of this install. there are many holes drilled in the horizonal walls/sides of the fiberglass. Need opinion on best filler/caulk to fill the small snap holes.

 

[keith c]

Sorry should be vertical not horizontal wall.

 

[tiltrider1]

Lots of solutions. 3m 4200 and put a screw in the hole. Epoxy filler, sand and paint. Make some decorative teak strips that cover the holes.

 

[angus99]

Suggest you avoid silicone. Jamestown Distributors has a ton of videos on how to fix damaged fiberglass.

 

[STB]

For fiberglass, I'd normally use epoxy via a syringe, then masking tape over it to keep it in, then sand. Then a little thickened epoxy as fairing, then sand, then prime and paint.

If just looking to fill the holes, I'd use 4000 UV (not 5200, which I only use below or st least near the water line, and not 4200 which isn't really good for full UV exposure.) It is a polyether caulk.

If looking for a less expensive alternative, you might try Dynaflex 230 or Dynaflex Ultra from Home Depot or Lowes. They are the top end of latex and a really amazing. In like best, especially ultra, where flexibility and movement over time are keys.

 

[PM]

It should be something rigid, fiberglass base. Not flexible or soft like caulk.

If the superstructure is white I would use "Marine Tex" it may take two applications because it seems to "dimple" when you spatula it into place.

If there are not too many holes and they are regularly spaced you could just run Stainless panhead screws into the holes. Or you could paint the screw heads white or match the color of your superstructure.

pete

 

[DDW]

Small screw holes? Use West Six10. It comes in caulking tubes, with a spout that mixes the components on the way out. The spout has a fine tip which fits in small holes. This allows you to fill the holes "from the bottom up" which minimizes the air space which is inevitable if you try to force putty in from the surface. Second, Six10 is viscous enough that it will not flow out of holes in a vertical surface (or even an overhead one). The thickeners they use in this product are somewhat unique, I've not been able to find anything like it elsewhere. Six10 is slow hardening, especially in small volumes and low temps. A couple of hours to gel at 70 deg and overnight to harden. In low temps a couple of days unless accelerated with heat. This means you don't have to work fast, it won't harden in the mixing spout quickly. Like all epoxies, it will yellow in the sun so you want to paint over it after it has hardened.

 

[syjos]

I would clean the hole with a Dremel or by running a drill bit into it, one size larger than the existing hole.

If you have access to the back of the hole, place masking tape on the back of the hole.

Mask the fiberglass around the hole.

Then fill the bottom of the hole with thickened epoxy but not all the way to the surface.
Leave a slight depression. Clean up any epoxy smeared outside of the hole.

After the epoxy cures, clean the hole with the Dremel or sandpaper. Remove masking tape and wipe the area around the hole with acetone or lacquer thinner and mask the area around the hole again. With small holes, I use a punch to make a hole in masking tape slightly larger than the the hole being filled and apply that around the hole.

Fill the hole with color matched gelcoat paste to slightly above the hole with a squeegee cut to a narrow size or putty knife. The masking tape around the hole will allow the putty to be slightly higher than the surface. If the gel paste doesn't have wax in it, cover the gel coat with Saran Wrap to facilitate curing.

After the gel putty cures, sand the hole with wet and dry sandpaper starting at 300 and progressing up to 1200. Don't oversand. Leave the masking tape around the hole until the fine grits to avoid scratching the surrounding surface. Sand until hole is level with surface. Apply wax.

If your gel coat is faded don't wax because it will make the patched holes shiney and stand out.

Gel coat paste can be color matched by Spectrum Color; spectrum-color.3dcartstores.com Send them a small sample of your gel coat and they will match it. If you have a popular boat, you can search by manufacturer and model year at the Spectrum site. But it's still best to send them a sample.

 

[koliver]

Several workable fixes above.
I have done this job. My boat is white. Though there are many different shades of white gecoat available, it was easy to find the right one to match, in a small tin.
I used a countersink bit to get rid of the ragged edge of the hole, and provide a clean hole all the way through the old gelcoat and into the cloth behind. Then mix a little cabosil or other compatible filler into the new gelcoat until it is thickened and fill the hole. A tiny bit proud will allow you to sand it level after it hardens. Use 2000 grit paper for the final sanding and then a fine cut polish to finish it off.
When I did this, I did about 20 holes at one time. It took about an hour for the basic repair for the whole works, then just minutes to sand and polish it. Now I can't find those repairs, even those I can locate accurately by reference locators.