The work continues. After removing the worst part of the anti fouling on one side we decided to continue with a sanding machine. Our cute “mouse” sanding machine was able to remove a post card size area in half an hour. Therefore we decided to go for more sophisticated machinery. Luckily our boats club has its own disc sanding machine which we could borrow. It had also an industrial vacuum cleaner to remove the fine dust that gathers during sanding. The only thing we needed to buy was the sanding paper for the machine. So we checked from the internet and our books which grade of the sanding paper would be suitable. We decided to go for grade 40 which is quite rough but based on the results from the mouse got the anti fouling off. At the stores we bought 5 packages of sanding paper with 10 papers each. Better too much than that we run out of paper during the job. After all we can return unused packages to the store. It turned out that we needed 30 sanding papers to get the anti fouling off. It was not so much the wear of the paper that lead to fast replacement but the layers of wax coated anti fouling where so sticky that they covered the sanding paper in patches and therefore removed most of the grip that was needed to grind further. The best results were achieved when holding the sanding disc in a slight angle so that one only sends with the edge of the disc and not the complete disc surface. We read about this also in the maintenance book and it brought clear results. Of course we were worried how fast the sander will take of the layers. Therefore we tested the sander on the part of the keel which was made of metal. It turned out that removing of the layers could be kept pretty much under control by applying various pressure. However, we noticed that the surface topography of the bottom was not uniform which led to spots where one layer stayed while I was grinding already to another layer right next to it. Usually boats have several layers of paint so one gets at least fast feedback if one sands too deep.
After a couple of evenings we got the anti fouling layer off. The bottom was in very good conditions except one area where we saw a crack in the paint. Around the crack we sanded to the fiber glass bottom which went pretty fast compared to the sticky layers of anti fouling. We applied epoxy filler over that area and after its curing time also that part was ready for painting.
In the internet we studied many times what bottom paints should be applied but it seemed like a never ending story especially as our goal was not to apply an anti fouling layer as the final touch as we do not need it in the lake. When reading through the specs of the paints there was the info what kind of base there should be for the paint and what layer should be on top of that paint. When reading through the specs of the layer that was suggested to be on top of that layer it turned out that there should be another layer or it ended with a anti fouling layer. In the end we decided to follow the course of the previous owner and bought Hempel Light Primer with two colors. The first color is used for the first layer of the boat. The second layer is applied after the recommended curing time of the first layer but as it has a different color it is easy to see which part is dry. As we ran out of the first color in the first paint job we had to apply the second color already at that stage. When applying the second layer we noticed how difficult it is to separate already painted areas from fresh painted areas if the color is the same.
Painting the boat was a rather quick process and was quite motivating as one instantly saw the progress. Between the the application of the layers one should wait one day so the first layer is not too wet or too dry. The only part that was not painted were the spots where the fixtures of the carriage on land keep the boat in place. Those are now squares at the bottom with the old blue surface. Those parts will be finalized next year and we can move the boat a bit forward in the carriage so they are not covered by the fixtures.
We applied two layers of Primer to the bottom and let them dry.
The painting of the boat was also under a tight schedule as the plan was to have the boat in the water when Aegir’s parents visited Finland in the beginning of June. One of the main goals of the visit was to make a sailing trip together with us. The weather was not too supportive with us in the beginning for keeping our schedule as the temperatures were close to zero in the beginning of May. The curing time of the primer was said to be 14 days if the outside temperature is 10 degrees and 7 days if the temperature is 20 degrees. Application of the primer at temperatures below 5 degrees was not recommended. Luckily the temperatures at the end of May increased almost to 30 degrees which enabled the paint to dry in time and to get the boat into the water before June.
By the was, it is not a good idea to leave masking tape attached to the boat for a long time at least one should prevent to get it wet e.g. by rain. It took a couple of hours of scraping and removal with cleaning liquid to get the stuff off.