Filling Small holes

[Llunker]

Hey Guys,

I have done quite a bit of work as far as scratches on gel-coat and have been able to repair those and re-apply gel coat with no problems and even had somewhat of a decent match on the polyflake with it. My question is I have a few small(1/8-1/4" holes) that were made from a Fish finder mount and I was wondering what you guys use to fill the small holes with?

Marine -tex? epoxy and resin? After i get it filled I will be able to re-apply a gel coat with a brush and wet sand it out and then polish and was it again.

Any suggestions

 

[Greg Mrozinski]

Re: Filling Small holes

Lunker,

If you plan on using Gel Coat, you will need to use a polyester fill material NOT epoxy (Marine Tex) since Gel Coat will not stick to epoxy compounds. I have used a marine form of Bond-O to fill and then top coated with Gel Coat. That works nicely. You will have to grind/sand out the holes some before filling and then build gradually finishing off with the Gel Coat and then wet sand and compound.

 

[Llunker]

Re: Filling Small holes

Yes--i had planned on re-applying Gel-coat to the outside to make it look as though there was never a hole to begin with. What is the Name of the Marine type Bondo that your are speaking of? What color does it turn out to be? I need a blue base color and then top coat it with polyflaked mixed gel-coat.

Thanks for the help bud

 

[drewpster]

Re: Filling Small holes

If the holes go in to the transom I recommend you use hardwood dowels to fill the holes. Just tap them in with some glue and cut them off almost flush. Once the glue cures grind the filled holes slightly below flush. Use a polyester based marine filler to bring the surface back flush and re- gelcoat. In my opinion the dowels are the only way the guarantee a water tight seal. Simply coating the holes over may allow water intrusion in to the wood that could develop rot. May seem like overkill, but you should have seen my transom when I removed it, rotten.

 

[Llunker]

Re: Filling Small holes

no not on transom--this is on the mount area at the drivers side console for the old fish finder. The holes are not in need of a dowel--they aren't that big and they are way above the water line.

I just want to know the name of a good marine bondo that will adhere with gel-coat and a base coat that would match my boat.

 

[Mark42]

Re: Filling Small holes

Mix up some polyester resin with a thickener like wood flour, or even cooking flour. Mix the resin first, then add thickener. Make it thick like peanut butter and press it in the holes good and tight. Then you can gel over it no problem.

I have used cooking flour to thicken resin when filling small holes or as a putty for filling low spots before finishing. It will hold up as well as wood flour and you probably already have some in your pantry.

Be aware that thickeners cause the cure time to be extended.

 

[drewpster]

Re: Filling Small holes

If you have access to both sides of the hole I suggest you fill the hole from the under side. Put the filler on the unfinished side and leave a slight depression on the finished side so there is a minimum of color matching. You can use just about any filler on a small hole. Just make sure it bonds to fiberglass and wont fall or run out before it cures. After you get it filled you can use a gelcoat patch kit and match the color. If you do it right, you will never know a hole was there.

 

[zip34788]

Re: Filling Small holes

Been there, done that! The best thing that I have found if your are going to re-apply gel-coat is Bondo Glass Filler. It mixes with a hardener for a durable surface. Other than for its dark green color which is sometimes difficult to cover with light color gels it provides for an excellent restoration. Bondo also makes an acrylic putty that will work for some applications.

 

[Llunker]

Re: Filling Small holes

Thanks Guys--thats what i was looking for.

Excellent --but now I might be putting a GPS puck there and will need a hole or two anyways--hehehehehe....Just got a new 997c SI HB. So Who knows --i might not have to fill a hole anyways--i might be creating more holes.

Much Appreciated guys

 

[Yacht Dr.]

Re: Filling Small holes

Hello m8s...

erm..none of these suggestions will work permantly...

quick fix..yea..mebbe if you know how to patch paste..

You have to grind and glass the holes..spray gel ( patch spray if you want to see it next season or whole spray your console if you dont )

Friends..ill tell you .... you Can NOT patch paste and have it live forever..you have to do what the pros do if you want a pro job. and it really isnt that hard if its a small spray area..just takes a little more time with some good quality material.

3m spends more on research and development then we make in a year.. hint hint....

YD.

 

[Greg Mrozinski]

Re: Filling Small holes

Lunker,

Sorry for not answering sooner. I used Evercoat Formula 27. It is white and can be colored with pigments to match other surface. Worked great and is waterproof; although they don't recommend use below the waterline.

 

[Southern Appal]

Re: Filling Small holes

I have several large holes located on the bow. The dowels would work for me. I cannot get to the underside, and I don't expect a professional type repair. Won't the gel coat seal the dowels well?

 

[drewpster]

Re: Filling Small holes

I have several large holes located on the bow. The dowels would work for me. I cannot get to the underside, and I don't expect a professional type repair. Won't the gel coat seal the dowels well?

Are the holes at the keel or in the deck? The dowel repair works well for a small hole. Larger holes can use plugs to seal the wood core only. A normal grind, fiberglass then gel repair should be applied to the fiberglass skin. Gelcoat alone will seal poorly.

I repaired the holes in this picture at the bow of my big boat.

I filled these a long time ago and I have had some problems in finishing them.
The deck is a plywood core covered with fiberglass. I used a hardwood plug to fill the larger hole on the left. It was about 1 1/4" in diameter. the mistake I made was in repairing the skin. I did not use any fiberglass. The resin shrank as it cured and caused a slight depression in the finish paint. If I had covered this with gelcoat, the result would no doubt be the same. To fix this I am going to have to go back grind down in to the wood again and lay some fiberglass and resin, fill and re-paint. I used epoxy in the repair because I am painting, not gelcoating. To use gelcoat you need polyester so the gelcoat will bond. (covered that already) If I had use polyester another danger is that polyester resin fractures over time. Thick coats of polyester without glass will fracture and allow water to seep in.
I am reluctant to say that small holes have the same problem. But the YatchDr. is a professional and very experienced. I am inclined to revisit that that idea and go with conventional glass/resin repairs when using polyester with gelcoat. Epoxy and paint is another story. But in cases of larger holes it is always a good idea to use some cloth with whatever resin you use.

 

[Llunker]

Re: Filling Small holes

Lunker,

Sorry for not answering sooner. I used Evercoat Formula 27. It is white and can be colored with pigments to match other surface. Worked great and is waterproof; although they don't recommend use below the waterline.

Thanks Greg--thats all i was needing to know