Craigslist score and mast tube repair

Thread starter #1
So I scored a free sunfish today she’s old and ugly, and got her warts, but she’s 128lbs and 2 screws away from being useable (sailable?).
Also came with 2 rudder/tillers and 2 daggerboards.
So the story goes after a mishap on the beach this women’s 1980 sunfish (which she owned since new) had damage caused to the mast step. Her son finds this older hull and retro fits the rudder to the older hull. Well now she moving on gave me the boat for free. When I see the 1980 it seems to be in great shape, light weight, stiff deck and hull. No cracks besides the mast step and the keel is pretty worn from the local rocky beach. So I wondering how hard is it to fix a cracked mast step. ?
Sorry I didn’t take any pictures. But the opening is dented and spider cracked with a crack/tear in the sleeve about 2-3” down.
Here are some pics of the freeby


beldar boathead

Well-Known Member
The freebie is old! From the mid 60s it would appear - possible older. The mast step in the other boat should be fixable with access via an inspection port. Some pix would help. Just to be sure Of the problem, fill the mast tube with water and see if it empties itself, and how far down the tube the water level ends up.
That's a relatively easy fix, an inspection port will allow you to make the fix bombproof by repairing the step tube on the inside, then strengthening its outer surface (through the inspection port) with additional layers of glass and possibly some clamps (the kind with protective rubber coating). Anytime a step tube has the sort of crack you described, in the wall of the tube itself, strengthening it is a good idea for safety's sake. Pictures of the damage would be helpful, the compound curve where the step meets the deck doesn't look too bad, you'll still want to clean that up and make it better, but I've seen far worse. If the other crack or "tear" you mentioned resembles the spiral crack of a newly-opened package roll of uncooked Pillsbury biscuits, you're gonna want to strengthen the step. If you block enough light by placing a towel around your camera, the flash should illuminate the inside of the step tube and let folks see exactly what sort of damage exists. Otherwise, good score, paint and varnish will work wonders along with some possible upgrades in line, hardware, etc. :rolleyes:
Thread starter #4
So I contacted the PO and I’ll be heading back for the other hull as soon as weather permits. She was happy to hear I was going to try and repair the boat as she’s sailed it since new, and felt it was a shame to junk it.

Originally I was hoping to find something to sail while I fixed my hull,so I wouldn’t feel rushed to get her back in the water. This other hull is in better shape then mine, minus the mast step of course. So now the plan is to repair the ‘80 hull while sailing mine.

I’ll be sure to post pictures when I pick up the hull,and I’m sure I’ll have plenty of questions.
Thread starter #5
Well here it is. The picture’s verify the women’s story. Apparently while being stored on the community beach someone placed a stone or stones in the mast step.
More then likely a young child playing on the beach. Along comes the PO’s niece with no knowledge of the stones and rigs the boat, not noticing how high the mast was in the step. Well wind catches sail and this is the result.
Besides that there’s some spider cracking where the block/hiking strap were attached, but other wise the original gel coat is in great shape. Unlike my hull which has plenty of spider cracking throughout.
The hull is so much stiffer then mine ‘78 made me realize how much support the foam blocks actually gives the boat.


Yikes!!! That's pretty ugly, but it CAN be fixed... might be easier to simply replace the entire step tube. Or grind away the trash and start rebuilding the glass. You may be able to pry or otherwise work that lower section back roughly into place, use files or specialized grinding tools for the internal repair, then work through an inspection port to wrap the outer surface of the tube and bolster it at the lower end where it meets the hull. You'll wanna clean up the outer surface of the tube as much as possible before you start wrapping glass matt & cloth around it. A little "fiberglass rope" may come in handy for wrapping around the base of the step tube, while matt & cloth should be applied in alternate layers for maximum strength. More on all that later, once you've reached that stage of the repair. Despite its ugly appearance, repairing that damage where the step tube meets the deck will actually be easier than the lower section, since it's much more accessible... you'll simply be grinding away all that worthless cr@p and rebuilding layers of glass as you rebuild the compound curve. Again, more on that once you've cleaned up the damage and ground or filed away the trash. That's your first mission, if only to better see the damaged areas and understand what needs to be done. You'll also need to install an inspection port for access so you can work on the (currently-hidden) outer surface of the step tube. Certainly a feasible repair, don't be intimidated by the ugly appearance of the damage, LOL. :eek:

Folks here will help you as you work through the repair, just remember that preparation is of critical importance in this sort of endeavor. Don't know how much glass work you've done in the past, but you can certainly make this repair and enjoy sailing for years to come. On my scale of "The Good, the Bad & the Ugly", this damage qualifies as Ugly, but I've seen worse, LOL. Remember, all fiberglass can be repaired and made even stronger than it originally was... it's all an equation which includes factors such as time, money, patience, etc., balance out the factors and you'll have a solid repair. CHEERS!!! :rolleyes:
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Thread starter #7
I’m not in a rush, so I have plenty of time to research and decide on how to handle the repair.
Yes an inspection port will be in order, that will be first on the list.
As for glass work I played with it before, fabricated a tail section for a motorcycle and repaired some fairings in a track bike, didn’t have to be pretty just not fall off in the track. I do high end home construction and specialize in drywall finishing, multiple coats to achieve perfectly smooth finishes and floating walls and ceilings. So I think I have some of the skills required, just need to learn the process.
Once I open the boat up I’ll know better, but one idea I have is to do a mast stepectomy from the older hull, and use it as a replacement. Again I’ll decide after I open the patient.


Thread starter #9
That’s why I’m here, use the collective knowledge of those more experience then myself, keeps the ideas coming!!!
I truly appreciate any advice the forum has offer.


Active Member
Should not be too hard to make a new mast tube by wrapping
fiberglass around the mast. Just remember you don't want a
snug fit as air has to vent when you insert the mast. Installing
the tube really requires you to pop the front deck so you can
cut the old tube out. Look at how the mast tube mates to the
deck flange, you'll want to duplicate this if possible so don't
cut the old mast tube off flush with the underside of the deck,
try to cut on the seam line. Hopefully you'll be able to slip
the new tube over the deck flange. You'll find the method
the factory used to secure the mast tube to the keel a screwed
up mess. Anything you can do will be a huge improvement.
Actually with a little work you can make the mast tube much
stronger than factory so you can sail in high winds without
rolling the dice on breaking something.
Thread starter #12
With the damage to the deck, and the mast step beyond repair, removal seemed the only option.
Take a look at the rocks jammed in the step. Even with the step split and on the bench I couldn’t remove the them.
So I think cutting the complete step out of the other hull is my best option. Unless I can source a new one somewhere.
Meanwhile it’s time to start drying out the hull.
Look a lot like a typical Laser repair where the deck is damaged. You may
be able to make the repair without sacrificing another boat. It should be
pretty easy to make a new tube from scratch. If you search Youtube for
Laser repair guides you'll find a couple of ways to do this.


Well-Known Member
Wow; that kind of damage to the mast tube may be a first one on this forum.
Thanks for posting!
Fer sure!

I'd cut out two oval circles involving the keel and upper deck area, mold a new tube but one in which an adjustment can be made to adjust its length. (Same size, top and bottom, and a sleeve to adjust for length, epoxying last to make the step the exact length and "twist" when reinstalling).

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the method
the factory used to secure the mast tube to the keel a screwed
up mess. Actually with a little work you can make the mast tube much
stronger than factory so you can sail in high winds without rolling the dice on breaking something.
When boats from the 60s thru today are still successfully bombing around in high winds I think the mast step construction by the factory should be considered to be just fine.
Thread starter #17
When boats from the 60s thru today are still successfully bombing around in high winds I think the mast step construction by the factory should be considered to be just fine.
Well I got the chance to cut out the donor mast step, and I’ll have to agree with beldar, that thing was rock solid. I had to cut though the keel and remove the resin and glass cloth in pieces. No wonder the mast tube snapped as opposed to detaching from the keel during the “incident “.
So here’s a shot of the donar organ...


You cannibalized another mast step after all... oh, well, that'll save you the trouble of building one from scratch. A few observations: you'll wanna clean up those areas where the step meets the hull and deck, and that compound curve up top where the other damage occurred. You want clean surfaces of solid glass for your repair, no crud or trash or rotten glass or tired gel coat, just clean glass to mate with clean glass for a strong bond. You might wanna slightly fair out surfaces which will meet as you progress with your repair. Eventually cut pieces of cloth (or matt) to spec and have them laid out ready to go for each glass application. Throwaway dust-free latex gloves, throwaway paint brushes and throwaway plastic tubs or glasses are your friends in this sort of repair. Clean rags and acetone are good to have handy whenever you work with resin & glass. :rolleyes:

Mix only as much resin & catalyst as you need for each step, no point in wasting expensive materials by mixing unnecessarily large pots. Avoid the common error of adding too much catalyst, which will give you a "hot pot" and cut down on your working time. Use latex gloves or a small rubber squeegee to help smoothen out wrinkles and air bubbles, which are verboten and cause weakness... swap out gloves as necessary during repairs, I used to keep a cardboard trash box handy so I could quickly hurl soiled gloves, brushes, etc. as I went along. Looks like you have the tool situation covered, but files, grinding tools and sandpaper will be helpful. You won't need them when you're actually applying resin and glass, just for doctoring or modifying cured material. Whatever task you're doing, try to keep only the tools and materials you need handy, as all other cr@p will simply get in the way. :confused:

Whenever you're applying glass cloth or matt, you first want to wet up the area where the glass will be placed, carefully lay the pre-cut pieces of cloth or matt as planned, then saturate the cloth or matt with more resin... you don't want any dry spots left in the glass, same way you want no wrinkles or air bubbles. Latex gloves come in handy when working on mast steps, you can use gloves to quickly yet gently eliminate wrinkles & air bubbles and spread any extra resin which may have dropped during the wetting up or saturation, aye? This is especially true when working through an inspection port, where your range of motion is somewhat limited. Dunno whether you're gonna do this, in fact I'm curious to see what sort of advice others give you for effecting this repair, particularly any suggestions as to how the glass cloth, matt or rope will be laid. That can make a BIG difference in your end results. Guess we'll see what others have to say... ;)


P.S. A small mirror like women have in their purses will be handy for checking results through an inspection port, might have to place a flashlight in the hull first at the appropriate angle and location. Rags work great for propping up small LED flashlights, aye? :D