A couple years ago I watched UNA’s foremast roll off the boat and land heel first on the concrete garage floor. There was a, “Crack”. Never good. Initial examination revealed nothing. I secured the pole back on the trailer. Not long thereafter when putting the boat away, I heard a rattle when I set the mast down before setting, I hear a rattle. This time I discovered a 18″ split between 2 of the staves where the mast was solid. At the time I decided to monitor it and ordered a fiberglass sock to repair the damage, but didn’t.
Many sails later, I found myself holding onto UNA with two-reefs and needing a third. We were bashing against wind, current and seas to gain shelter in Pulpit Harbor on Deer Island. That split was front and center in my thoughts. Thankfully UNA came through, but I had haunting doubts next time. I needed to fix the mast.
Once home, it was obvious the crack had lengthened. Another problem was the mast would swell and stick in the step on occasion demanding wrestling and wiggling to unstep. Putting a plastic bag on the foot had solved that hassle for too long. So, I hand planed the heel and sanded the problem section with the ROS and 80 grit to 16″ above the deck. The stick was then saturated the wood with straight epoxy and 2 layers of the fiberglass sock were snugged on. Epoxy splashed everywhere. The 90 degree heat rapidly accelerated the epoxy’s flash point. I panicked and ran for packaging tape and saran wrap to hold the works in check.

After an overnight set, I cut and peeled the plastic off. Some had doubled onto itself and became embedded in the epoxy. There were also a few air bubble craters.


Alternating stints with the belt and ROS sanders got things back smooth, though I questioned how presentable the fix would be.


Glad I donned a mask. Dust was everywhere. Wish I had worn long sleeves. The itching began. After wet sanding (kept dust down), the results improved. I thought I’d have to paint the mast.

Some of the outside layer of fiberglass was sanded off, but only slightly. Most of the dust was resin. One more coat of epoxy, a quick light sanding and 3 coats of varnish gets us whole again. Glad to cross this one off the list and now I have more confidence in UNA’s defense against the next blow.

Good tip about the glass sleeve material. I have an old Moth Boat mast with a foot long split in one side the luff groove at the bottom where the sail feeds in. I’ve partially repaired it with goop and clamps and was going to wrap the repair site with 4 oz glass cloth set in resin, but the sleeve looks like a much tidier approach. One of the material suppliers offers a “heat shrink” wrap to place around the sleeve as a way to apply pressure without bothering with a vacuum bag. The heat shrink wrap might avoid sticking as was the case of your plastic wrap. Just a thought.
Not familiar with the heat shrink material. Got a brand or supplier? Is it like peel ply? I picked the wrong day to do what I did. Too hot and was too rushed as a consequence. I’ve long followed your moth blog. Nostalgic. Sold my classic Fletcher Cates (?) to pay for UNA’s trailer. Was a fun boat to sail.
Fiberglast is the company with the shrink tape–I have not tried it yet: https://www.fibreglast.com/product/Shrink-Tape/Vacuum_Bagging_Films_Peel_Ply_Tapes
This is the outfit I plan to order the sleeve from: https://www.sollercomposites.com/FiberglassSleeves.html?gclid=CjwKCAjw_b3cBRByEiwAdG8WqhkTpj_uQEb1nSp-qZWj5-D9sK_PLcYSZ0b71OzU2UffRDo9YVFkrxoCIBkQAvD_BwE
Cool. I got sleeve from Duck Works: http://www.duckworksbbs.com/product-p/a-p-bbfs-parent.htm