I cut 2 holes in my Sunfish!

I was nervous…. a bit hesitant.  it felt awkward, maybe even unnatural, but there I was drilling at first a small hole, and then slicing a large circular piece out of a what seemed to be a perfectly good boat.  but a part of me knew it was necessary.

I haven’t gotten a chance to officially weigh my Sunfish, but I have a sneaking suspicion that she is quite overweight.  the most likely culprit – water.  I try to drain her after every sailing excursion, but don’t know that it ever worked that well.  with a 40-yr old boat, it is also quite likely that I have some leaks – areas where water can get in while I am sailing (I also haven’t tried a leak-test yet).  and, I fear that storing it outside at my fathers for a year or two might have been a bad idea (my idea, not his – I don’t blame you Dad!).  I had covered the boat with a tarp, but the wind and rain still found a way to attack my poor Sunfish.  putting that all aside, though – the issue I think is largely absorbed water.

for those of you who aren’t familiar with method of construction for these little sailboats, left me explain (to the best of my knowledge):  the hull (bottom) and deck (top) are both made of thin built-up layers of fiberglass.  the interior of the boat is mostly hollow, but is stiffened and strength by a series of foam flotation blocks that also provide emergency flotation, so that the boat is mostly un-sinkable.  these foam flotation blocks are made of a closed-cell foam – which are normally pretty water-resistant, but over time, will slowly absorb water through osmosis.  these foam blocks are held in place with a 2-part expanding foam.  see the picture (from the Sunfish Forum) showing the interior of the boat as currently constructed.

Click the image to open in full size.

the recommended method to fix the water-logged blocks is to cut some inspection ports (holes) into the boat and use a fan or something of that nature to force air through the inside of the boat.  the air movement will help to dry out any remaining water, as well as to slowly reverse the osmosis process and pull the water back out of the foam blocks.  I probably should have done this a long time ago (and I actually bought the inspection ports a few years ago, just haven’t gotten the chance to do the work).

so this weekend (10/10/2009) I finally got around to cutting the holes in my ‘Fish for (2) 5″ inspection ports. I just traced the outside of the port with a marker, and then drilled a 3/8″ hole to get started.  I then used my roto-zip tool to cut the circle out in the fiberglass.  the roto-zip worked spectacularly – I just wish I would have remembered to wear long sleeves – the dust was awful.

the 1st port I cut on the deck, just behind the coaming/splashguard, and just forward of the daggerboard slot.  this is usually recommended as a good starting location – because it will provide good access to the daggerboard slot as well as the mast tube towards the front in case repairs are required.

Img0152044for the 2nd port – I wanted to avoid putting the inspection ports all over the deck, so I opted to place on in the wall of the cockpit.  since my Sunfish is pre-1971, it does not have the little storage compartment below the deck in the back of the cockpit – so I opted to install the 2nd port there.  this gives me access to the rear of the boat, and will also allow me easier access in the future to install the hardware for a hiking strap.  the picture shows the flange of the inspection port – I haven’t installed it, only dry-fit to test the hole.


both ports fit great – and should be pretty easy to install for good, but I’m leaving them out for now, and for a couple reasons.  the interior flange on the ports reduce my access to the interior of the boat, so I will probably leave them off until I have finished any (and all) repairs over the winter.  plus, they work well to hold in a few scraps of screen – I’ll use the screen to keep air flowing through the boat, but keep out most insects and mice or whatever else might want to hide in there!


that’s pretty much where the good news ends… when I first started looking around inside the boat, I noticed some standing water.  not a lot, but it was definitely damp inside the boat.  I used my small wet/dry shop-vac to suck all the water out and sweep up all the fiberglass shavings from cutting in the port.  I then checked the foam blocks – the right side block seemed okay, but the left side block was loose at the bottom… NOT GOOD.  plus, the 2-part foam at the bottom of the boat was quite wet, and some of it was no longer attached to the bottom of the hull, so I snapped a couple of the pieces out.  I figure it wasn’t attached anyway, it was away from the foam block (so really just over-spray), and any extra weight I can get out is an improvement!  sort of looks like breadsticks… ugh.


here are some views from the inside – I was able to carefully slide my DSLR camera in through the hole on the deck (my brother is going to bring over his smaller point-and-shoot style camera – hopefully I can get some better pictures to post later).  first 2 pictures are looking back towards the right and then left side of the daggerboard trunk.  it looks almost like the 2 part foam is drooping down for the deck – I’ll have to feel around in there, and see if that is loose as well (I have a feeling that is NOT normal).



this picture is looking forward towards the mast tube – that 2 part foam looks nasty, doesn’t it?


this picture is looking through the 2nd port in the cockpit wall towards the back of the boat.


I’m not going to lie… I’m pretty bummed.  I knew it was probably overweight (probably a lot), but I just somehow hoped it wouldn’t be.  the outside of my Sunfish is deceptively pretty nice, especially for being a 40-ish year old boat.  I’m keeping my hopes up, though, and we’ll see how effectively I can dry it out.  I plan to store it in my dad’s barn this winter, and will probably have a fan running on it constantly.  after I’ve dried it out quite a bit, I will have to figure out a way to repair the foam blocks and make sure they are all adequately attached.

before I close it all up, I’ll probably do the leak-test as well, and try to repair any leaks to prevent this water-logging disease from coming back to haunt me.


20 Responses to “I cut 2 holes in my Sunfish!”

  1. 1 RL October 15, 2009 at 8:56 am

    This is the post i’ve been looking for!! Thank you so much for this How To w/ pix…
    i’ve been hesitating to cut into my ’84 Sunfish b/c i know it is taking on water… (My ’70s model fish had 6 ports already in place when i bought it…but i think the 2 you recommend are all i’ll need.)
    this is great.
    thanks again!


  2. 2 len December 5, 2009 at 9:24 pm

    this was GREAT! i have an older sunfish myself, on the order of yours. for a winter project was tempted to take off the entire deck to repair water leaks. your photos are have answered my questions as where to put the inspection ports, and as to what is inside! thank you very much, len


    • 3 my2fish December 5, 2009 at 9:49 pm

      glad I could help. everything I’ve read online strongly discourages taking off the entire deck – I’d try the inspection ports first.

      thanks for reading,


      • 4 Keith April 19, 2010 at 4:07 pm


        With the addition of your inspection port in front of the dagger board can you reach in and access the front of the cockpit to add a hiking strap mount?



      • 5 my2fish April 19, 2010 at 7:14 pm

        Keith, my Sunfish is still in the barn at my dad’s house, so I can’t go and check it for you right now. I have a feeling you might be able to reach back that far, but it’d be pretty tough. but if all you need to do is hold a stainless steel backing plate and a few nuts to bolt everything together it might work…. you’ll probably need a helper to do the work on the outside while your arm is all tangled up inside the ‘Fish, though!

        have you seen this picture from the Sunfish class website?
        my Sunfish is old enough that I don’t have the cubby-hole in the back of the cockpit, so I’ll use my back inspection port in the cockpit wall to install the lower/back hiking strap attachment, and I was probably going to just attach the front/upper hiking strap attachment to the cockpit lip, similar to the side view shown at the top of the image above. but, if I CAN reach back that far, I might try what you’re suggesting. if you haven’t already cut the hole in, you might be able to move the port a little bit further back, but I didn’t want to be too close to the daggerboard slot.

        good luck, my2fish


  3. 6 Whitney February 21, 2010 at 8:34 pm


    my daughter and i cleaned and dried our sunfish a couple of years ago – sorry no pics. we found tons of how to do it notes and drawings that took away the guesswork at this website. http://groups.yahoo.com/group/sunfish_sailor


    • 7 my2fish February 21, 2010 at 8:41 pm

      whitney, thanks for visiting! I’m glad to hear you had some success with the drying out process. I’ve been reading the Sunfish Yahoo group for a while now – I’ve read a lot of the stuff in the historical messages, as well as the “Files” section. The Sunfish Yahoo group and the Sunfish Forum are both FANTASTIC resources.

      cheers, my2fish


  4. 8 classicalgas April 12, 2010 at 8:16 pm

    I’ve seen this done on a couple of friend’s fishes. And to avoid having to do this, this is why I’ve gathered up my boat and brought it home from dad’s. So far, I think I’m pretty good. But there are some hair line cracks in mine and I’m a little nervous.

    But this blog was excellent! I’ve always wondered what it looked like inside!


  5. 10 ken June 20, 2010 at 7:01 am

    One question with which I hope you can help. If I leave my Sunfish at a lake mooring,can it sink via a heavy overnight rain? It’s not mine and since a friend is lending it for the summer, just a bit worried.



    • 11 my2fish June 20, 2010 at 7:51 am

      ken – I think that the foam blocks are meant for flotation (as well as stiffening the hull), so I think there is supposed to be enough foam so it shouldn’t sink. that being said, I think there are other issues with leaving it moored that would be better to avoid – if it is very short-term, I wouldn’t worry about it, but long-term, leaving the Sunfish in water can damage the gelcoat, as water is slowly absorbed through the hull. also, if you have even a small leak in the hull, the water will slowly leak in and fill up the boat – it might not sink it, but it will sure slow it down! and make it really hard to lift out of the water as well.


  6. 12 nicolaas k July 9, 2011 at 8:05 am

    Thx for the pics. My 1962 sunfish has had poor upkeep over the years.Credit to ALCOT for a very high quailty product, no other sailboat would still be floating. Now starts the restoration with inspection ports, fiberglass repair etc thanks to all for the info


  7. 13 Robert Brewbaker July 20, 2015 at 8:07 pm

    Wonderful thread. Leads me to my (somewhat related) challenge. I have a mast that sloshes with what sounds and feels to be a 1/2 gallon of liquid (water I guess) inside the mast. But at no angle can I get even a drop to drip out. Hmm. How did it get in there? More pressing question: How can I get it out? I’m not inclined to drill a hole anywhere in the mast, even in one of the caps, ’cause I don’t want the darn thing to sink the next time I keel over. Any ideas?


  8. 16 73 fish August 4, 2016 at 9:36 am

    I have my ports and am working up my courage to attack this project, how did it turn out? My boat is a 73 and two of us can no longer move it.


    • 17 my2fish August 4, 2016 at 9:56 am

      73 fish, it turned out great. The foam repair worked really well. I never did any major hull repairs to make sure it wasn’t still leaking somewhere though. I ended up finding a 2000 Sunfish for a steal of a price, so haven’t sailed this older one since then. But I’d say go for it! And leak test it for sure to find how water is getting inside the hull.


  1. 1 winter storage « my2fish: a blog about sunfish sailing Trackback on October 19, 2009 at 9:26 pm
  2. 2 foam block reset « my2fish: a blog about sunfish sailing Trackback on August 16, 2010 at 6:04 pm
  3. 3 sunfish inspection port & hull drying fan « my2fish: a blog about sunfish sailing Trackback on May 22, 2012 at 8:29 pm

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

Enter your email address to subscribe to this blog and receive notifications of new posts by email.

Join 1,530 other subscribers

my2fish archives

my2fish stats

  • 669,064 hits

%d bloggers like this: