When to Sand your Pygmy Kayak - Order of Sanding Steps

Another tip for custom building a Pygmy Borealis XL kayak: A few posts ago I mentioned that I change the order of sanding operations from how they are mentioned in the official Pygmy manual. Following the order of sanding below I feel results in a smooth boat with less fuss. 

It also has two distinct advantages: 1) It makes it easy to fully sand underneath the coaming, and 2) it makes it much easier to get a smooth glassing job around the sides of the #4 panels.

Order of Sanding: When to Sand the Hull & Deck

The manual has you add two filler coats when you glass the hull, then it has you glass the deck, and you don’t sand the entire hull until the very last step before varnishing. We can do better and get a much better and smoother finish, but you have to be a bit more detailed.

1.      Glass the hull with your initial epoxy coat and squeegee it out well. Let dry a few hours.

2.      Trim the excess glass off the bottom of the #4 panels when it reaches the “green stage”.

3.      Add one fill coat to the entire hull. Let set up a few hours.

4.      Add a second fill coat but ONLY to panel’s #1-3. Do not add a second fill coat to the #4 panels.

5.      Let cure well. At least 24 hours and until not sticky whatsoever. Several days would be best.

6.      Now sand the #4 panels flat. Be careful to not cut too much into the glass. In fact, just barely flatten the panels as you will be adding another fill coat later after you glass the deck. Make sure that the top 2” of the #4 panels are flat and smooth. You’ll be adding the cloth from the deck onto this portion.

7.      Do the steps in the manual through glassing the deck. When glassing the deck make sure to bring the cloth over the deck and onto the #4 panels by an inch or so just as instructed in the manual. Follow the instructions for using the masking tape to pull up the excess cloth. It works pretty well. Let cure 24 hours but no more.

8.      Make sure that the deck cloth on the sides is dry and not sticky at all, but then as soon as you can (within the first 24 hours if possible but not more than 48 hours later) sand the tops of the #4 panels just to feather/blend the deck cloth down onto the #4 panel and to sand out any white cut line there may be.

9.      As soon as you’re done then add another fill coat to the deck AND to the #4 panels. Let dry for several hours.

10.   Add a second fill coat to the deck and to the #4 panels again as well. Yes, this will essentially be a third fill coat on the sides but you want that extra bit as the sides are easy to sand too much.

11.   Let cure very well. At least 24 hours and until not sticky whatsoever. Several days would be best. 

12.   Now sand the entire hull. Keep your ROS (random orbital sander) FLAT against the panels and do NOT sand the seams. You can hand sand them gently later.

13.   Now continue with the official manual and do the coaming, etc…

Sanding in this order will give you a very smooth boat. It will also allow you to sand in the area that will be under the coaming which is hard to sand if you follow the manual’s order. If you follow the manual’s order of sanding you will possibly build up too thick of a coat on the #4 panels and have a hard time blending the deck cloth onto the #4 panels without sanding away too much cloth. Our sanding ordering allows for a smoother and more flush deck fiberglassing job.