Soft spot on the roof – Part 2

Today’s objective was to cut the roof and find how big the repair needs to be. It will allow us to buy the new core (Sam is planning to use some corecell), fiberglass and the mat needed for the upcoming steps.
 

It's still snowing over here, so we brought a camping heater. Yes yes…it was snowing outside. Maybe it’s not a so bad thing after all that we are working from the inside! We didn't have a lot of ventilation to keep the warm in, so we wore a mask all the time since the fiberglass dust is very toxic! 

To keep the deck intact, we needed to cut carefully, not knowing the overall thichness of the balsa used. We used a Dremel saw max with a diamond blade, which allowed Sam to have the cut exactly the depth he wanted. He started  with a 1/8 inch depth and cut a square around the wet spot we identified on the first day.

When we pulled a bit on the fiberglass, the whole square just felt by itself. We could see the rotten balsa wood that was in a pretty bad condition.  It also confirmed us that the depth of the cut was perfect and that Sam did not cut through the top fiberglass layer – insert your favorite releaving quote here…!



We inspected the 4 sides of the square with our fingers; the balsa was so wet that by gently pressing on it, water was dripping out. We used a screwdriver as a lever and saw right away that all sides of this hole were delaminated.  Thus, we had to enlarge our repair zone… (quite a lot in fact!

The change in color shows where the plywood was

At some point, we discovered that the core was changing from balsa to plywood; which is a good news for Sputnik. Since we knew the winches positions had change over the years depending on previous owners taste, it is a good thing to know that at least, they are fixed in a solid material. From what we can tell, the plywood seems to be on both side of the companionway and seems to run forward from the cockpit to at least the mast, leaving only the top portion of the roof to be in balsa.


When Sam made his researches prior to this repair, he learnt that the joint between balsa and plywood are usually sealed with resin. We could see that joint, but the delamination on Sputnik’s roof was so bad that it created a gap big enough that the water reached the plywood too. The plywood was so wet that there is no way a fan could dry it. It will need to be changed as well

We used a paint scraper and an oscilliating tool to remove the balsa that was still sticked to the roof. We were afraid that putting to much pressure would rip out our last layer of fiberglass. This would make the repair much more complicated in the sense that it would then become visible from the deck. Quite honnestly, we don’t trust our aesthetic paint skills that much so far!

We opened and opened again, until the balsa was dry and that the fiberglass and balsa were tightly sticked together. In the end, the size of the repair is about 4 feet long by 2 feet wide. The plywood is still a little bit humid but there is no delamination. We’ll let it dry for a week or two and we’ll see if we need to open it more.

We cleaned up our mess and left with a piece of the roof, so we know which thickness we need to buy. That went well. Now, definitely no one is allowed to walk on the roof !!!

Time spent : 4 hours
Purchases:

• Dremel saw max : 120$
• Oscilliating tool : 125$
• Scraper for oscilliating tool : 12$
• Masks & glasses : 50$

Total time spent so far : 6.5 hours
Total cost so far : 332$