Crack Repair

[frank balcer]

My 1974 Pearson 30 has numerous spider cracks and nicks on the decks and cockpit sole.I purchased a dremel tool to grind out the spider cracks. My plan was to fill with Marine Tex, grind/sand smooth and then roll an tip with two part epoxy paint. Fellow at our marina says that the marine tex is hard to work with due to its hardness and if your not careful you can cause low spots around the area your working on. I like the idea that Marine Tex is waterproof as i will take a few weeks to get surface repaired before i will be able to paint. My question is there any other products out there that have the durability of Mareine tex but easier to work with? Thanks in advance all....

 

[Ross]

I would probably choose west 409 filler with vinylester resin. It will sand reasonably and will cure waterproof.

 

[sand sailor]

gelcoat filler is made just for this and you can get it to match from the manuf.
i talked to the guys at tanaya boats and he matched up a quart for me for $40. and was thrilled to know i was taking the time to do it right for a boat of that vintage

 

[Jim]

I think the marine tex will work find. It is waterproof too. I use it a lot. I refair my keel with it and it worked great.

I would use gelcoat or nothing to cover the filler unless you plan to paint the entire boat....

But, I think Ross is right! 409 filler with vinylester resin should work better if you plan to cover the repair with gelcoat or paint. I found this in the Marine Tex Web site.

How to apply gelcoat over epoxies (Marine Tex):
-Applying polyester resin (like gelcoat) over epoxy is very tricky and must be done extremely carefully. The smaller the repair, the easier it is to coat epoxy with gelcoat. The larger the area, the polyester will be more difficult to work with and more likely to malfunction (not cure).
-Mix and apply the epoxy to the surface to be repaired. Be sure to use the correct proportions and keep the application at a minimum of 70˚F.
-Let the epoxy cure for a minimum of 48 hours. Leave more time for curing if temperatures are between 68˚ - 60˚F. (At least 72 - 96 hours.) This time for curing allows the amine blush (a waxy surfactant) to come to the surface.
-Clean the surface with warm, soapy water.
-Rinse with fresh water.
-Check to see if the blush is completely removed.
-Lightly sand with 120 grit sandpaper, clean again.
-You will now be ready to apply the gelcoat.

 

[Maine Sail]

Frank..

You were given very good info. The problem with any of the epoxy products when used with older gelcoat is that the old gelcoat will sand away very, very easily and the Marine Tex will not and as you stated you will get thin spots. One way to avaoid this is to use razor blades, jewelers files and sharp chisels to bring the Marine Tex in plane with the gel before beginning to feather it with sand paper.

If you want to use Marine Tex I'd advise you that it would be cheaper to use West System or System Three and a filler. I like cabosil (colloidal silica) becuase it sands fairly easy and does not tend to bleed through a new paint job like microbaloons can though micro baloons does sand easier.

 

[Jim]

Question for Sail Maine

I had some damage to the unprotected stern corner of my Catalina. I have never understood why the didn't protect this area like Hunter does.

I got the fiberglass guy at the yard to make the repair because I want it to look perfect. They over filled the damage area with a porous material that looks easy to sand. Any ideas what they used?