Grinding Voids and Filling

September 7, 2015

Having a good block of time today to work on the boat, I set out to finish grinding out the voids in the laminate, as well as removing those areas in which the gelcoat was seeing severe cracking and separation.  Using an angle grinder and a 40-grit flap-wheel disc, I made a slow pass around Alva Anne's bottom, getting rid of problem areas as I went. 

The starboard side had a number of "issue" areas, but they were, individually, smaller than some of the areas on the port side. 

I worked my way from stern to stem, but left what may be lurking beneath the boat stand pads for another day.

After reaching the bow of the boat, I transitioned over to the port side.

On the port side there were many larger areas that needed to be ground out, mostly on the aft section of the keel.

My impression of the laminate, in areas I want to stress, was that the factory did a poor job of ensuring that the laminate was fully wet-out.  I did find a number of pinholes and what appeared to  be dry cloth.  In those areas, I ground out the bad laminate and holes until I reached solid glass.  On a few of the areas, I would ultimately take the laminate down a good quarter of an inch to a half inch, those these severe areas were few in numbers.

The gelcoat varied in thickness.  Generally, the gelcoat would start out with being applied thicker at the aft and then slowly reduce in thickness moving forward.  The gelcoat suffered a few large areas of cracking and chipping.  A light pass of the grinder over these areas would provide enough action to remove the loose pieces. 

The port bow had very little issue, at least for me.  It did appear that numerous voids had been filled by the previous owner, or a hired hand at the local boatyard.  

In all, I believed I mixed about 12 separate batches of thickened epoxy; each batch consisted of three pumps off the metering machine, followed by the addition of micro-balloons to bring the mixture to the ubiquitous "peanut butter" consistency.  :)  

Again, I moved across the starboard bottom, from stern to stem, filling as I went.  

I used a 4" squeegee to apply the thickened epoxy, and, in terms of application, attempted to fall somewhere in the middle of too light and too heavy.  I will have at least one more round of filling, and quite likely two more rounds, before the I consider the bottom fair.  I finished with the starboard side and quickly moved over to the port.

As I stated previously, the port side had a few larger areas that required filling.  In these larger areas, I used a 10" squeegee to span the larger diameter depressions that I had ground out.  However, most of the port bottom, like the starboard bottom, were easily handled with the 4" squeegee.

The gelcoat appeared to be in much worse shape on the port side, thus the larger filling patches pictured below.

I finished up toward the bow of the port side with skim coating larger areas that had poor gelcoat adhesion, and then called it a day.  I will be coming back later in the week for a pass on the random orbital sander with 80-grit paper.  It feels good to be re-building the bottom and to have made that critical milestone in the project where you move from tearing down to building up.

Total Time: 6 Hrs.