Gel Coat Crack Repair (continued)

[Dana Arenius, Virginia, C]

Hi Folks,

Thought I would drop a quick line to let you known how my deck gel coat repairs are doing. I recieved my order of matched gel from GCP,Inc. I ordered a quart of white which was waxed (for air dry). Half was whipped into a paste which is helpful for anything in a vertical or deep crack. I called the color match "1985 Cape Dory White". They put a product record number #042997 which was the date it was first produced.

I began with those cracks in the cockpit skupper areas. The color match was EXCELLENT even when the gel was created from color plugs taken when the boat was new and the boat is now into its 13th season.
I used a DRUMEL tool with a #105 engraving bit (1/32 inch diameter) to widen the cracks to get the gel all the way into the laminate. A simple artist brush was used to apply both the gel and gel paste. I minimized the repair area and built the gel up to just above the surrounding surface. Letting the gel dry for a day, I wet sanded it with 240 grit, then 320, 400, and finally 600 grit sandpaper to take it down equal to the surrounding surface level. It is the 400 to 600 grit sandpaper which really gives it the new shine look.

Having seen the outcome of skupper area, I am now turning my attention to the non-skid area in companion way bridge.

Just a point of interest. Many of you probably know that Cape Dory used a "black layer" between the gel and laminate. The dark color allowed one to easily see bubbles and eliminate them during the hull or deck layup process. I took a look thru the clear glass from the underside of the deck in the cockpit area. There are no stress cracks in the laminate. Still very solid and clear. Frankly, I have felt that the Cape Dory gel coat was very hard (compared to other boats) even when the boat was new. It may not expand and contract as well after a number of years.


Dana



arenius@jlab.org

[Dana Arenius, Virginia, C]

Hi Folks,

As I may have mentioned before, I am now looking at repairing my non-skid gel coat cracks. This is a bit more "tricky" since the surface is more textured. It is a colored gel coat, the non-skid is more faded, and the surface will see a lot of traffic on my companionway bridge.

In my mind the following questions came up in looking at what to do:

1. Can I match the colored gel coat color? I do not have color chips of the deck and of course the color is faded.

Answer: I considered filling the cracks with standard colored white gel and finishing the top with one part or two part polyurethane. I found that Z-Spar Miracote "Grand Banks Biege" in one or two part is VERY, VERY close to the color. I had a non-faded non-skid area under the lip of my engine compartment hatch cover. One can not distinguish the color difference if a 6"x6" square painted test "chip" is laid on top of the deck. A number of manufacturers make a "Grand Banks Biege" (Interlux, Pettit) but these are NOT the same color. I was still worried about durability of paint to traffic (I do not like to repaint a lot).

2. Should I use a colored gel coat or polyurethane?

Answer: I talked to a number of folks and looked at their boats in my marina who have painted and maintain their deck paint from year to year. I personally decided to purchase colored gel, fill the cracks with the colored gel, and respray the non-skid with the colored gel. I felt this represented the most durable and lasting finish. So I set myself up to try to spray gel coat on a test piece at home to see what it was like. I used the Preval sprayer cartridge and glass container combination (available in many home hardware stores and marine catalogs (West Marine)). The sprayer had gel coat listed as a product it could handle but left the mix amounts to what the gel manufacturer suggested. Gel Coat Products suggests about 15% acetone to the gel coat to be sprayed. I measured a small batch of gel (about 6 tablespoons of the white I had bought) and about 1-1/2 tablespoons of acetone. This was a bit more than the manufacturer suggested but it was necessary in order to get good spray. I made sure the catalyst was well mixed!!! Then I put on my safety gear (cartridge filter mask and eye protection. I sprayed it on a spare piece of fiberglass and it worked great. Just a bit more difficult than paint spraying but it was very controllable. I then decided to make my colored gel coat matched to the Z-Spar "Grand Banks Biege". I could then fill and recoat with the same color as the existing deck. Wear and tear on the recoat would only show the orginal color underneath which for all intended purposes was the same color. I also found that by controlling how much I pushed the painter sprayer button down, I could also form a small amount of splatter which could possibly be helpful to give re-texture to the repaired cracks. The good news is that Cape Dory used a random, fairly flat textured pattern in the non-skid. Other manufacturers used a patterned knit design in the non-skid and that would be much more difficult to match.

So I am now off to order some colored gel coat.....


Dana



arenius@jlab.org