Drilling screws to install inspection port....

Thread starter #1
I very recently cut out an inspection port hole on the interior of my Sunfish's cockpit area. Although I was more than a little nervous beforehand, it worked out just fine with a rotozip saw. I did have somewhat of a hard time creating a depression or dimple for the saw to initially catch to make the first cut through the boat--I ended up using a center punch, which I had to hit pretty hard to make a dimple. Although this essentially worked, in retrospect I'm thinking this wasn't the greatest idea in the world since the fiberglass could have cracked. Now that I have to drill six screws in to affix the inspection port, I'm wondering how I'm going to do it. I haven't drilled screws into fiberglass before, but it seems like getting the screw or even a drill bit to catch on such a slippery surface is going to be tough. Do people in the forum use a very thin drill bit to make an initial hole/dimple? Once I can create even a tiny hole, it seems like I should be home free.....
 
#3
Yes, drilling through the fiberglass is easy. The drill would have started your cut out hole easily, too. I make sure the screw-on port cover is tightened, then line up the port so 'open' and 'close' are centered (right tight, left loose). Many times I see the covers aren't centered- guess I'm a bit OCD about that. You can drill the holes first, or after you've attached the ring with 4200 or a good silicone sealant. Dip the screws in sealant, too. If not sure, watch Kent's youtube video. Use the holes in the port ring as your guide. No need to gradually increase hole size- I think it's a 1/8th bit for a #8 stainless screw (not positive on that). The hardest part is the awkward reach into the hull to attach the washer and nylock nut, especially if it's a 4" port (and I wouldn't use anything larger in the cockpit area). I drop the nut into the hull every time, curse, then waste time til I find it again- it's amazing how they seem to vanish from a 6" drop.
Tighten til snug, but don't over tighten, as it can crack the ring or distort the shape, then the cover doesn't screw on properly.
Add a bag to your port and you've got a handy stow-away.
 

L&VW

Well-Known Member
#4
A mark with a Sharpie should get you close enough, or use a ¼" drill to mark the gelcoat, then a tiny bit to keep the final ⅛" bit centered.

When I installed The Ultimate Port, I was surprised to find how thin the fiberglass was. Especially considering the occasional "insult" when stepping :cool:, slipping :confused:, jumping :oops: or falling :eek: into the cockpit. ('Course a bad trailer bed can punch the floor from the other side, and make bad spider-cracks, or, in one of my (now 5) "seasoned" Sunfish, a complete fracture :eek:. (Allowing rainwater to gradually seep into the inside).

The piece I removed was also not that "bendy" (for as thin as it was). This was as far as I would bend this 6"x14" piece, before having a fracture. If the cockpit is the same thickness as the deck or hull, I'd treat every damaged area as bigger than it appears.

(I may have time today to "mike" the deck, then later, "mike" the stored cutout piece). I've stored the piece, as someday, I'll use it in a repair as a "backup piece".

P8110032.JPG


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signal charlie

Well-Known Member
Staff member
#6
That's a tight area to work in. If you want to do machine screws, I would drill a 1/8 inch starter hole, and then put in one #8 screw to hold the port in place, using the drill to drive it. It will be snug. Or drill the hole one size larger. Drill another hole and put in a screw. Drill the rest of the holes. Then remove the port and screws and lay down your sealant. Reinstall the port and snug down the screws.

There is a sweet spot to getting screws that are long enough to get the stop nut started, but not so long as a socket won't fit over then. We keep a deep socket on hand just for those screws.

Or use stainless wood screws or pop rivets. Probably a better approach if the port is small. Wood screws will scrape unsuspecting arms and hands.
 
Thread starter #8
Yes, drilling through the fiberglass is easy. The drill would have started your cut out hole easily, too. I make sure the screw-on port cover is tightened, then line up the port so 'open' and 'close' are centered (right tight, left loose). Many times I see the covers aren't centered- guess I'm a bit OCD about that. You can drill the holes first, or after you've attached the ring with 4200 or a good silicone sealant. Dip the screws in sealant, too. If not sure, watch Kent's youtube video. Use the holes in the port ring as your guide. No need to gradually increase hole size- I think it's a 1/8th bit for a #8 stainless screw (not positive on that). The hardest part is the awkward reach into the hull to attach the washer and nylock nut, especially if it's a 4" port (and I wouldn't use anything larger in the cockpit area). I drop the nut into the hull every time, curse, then waste time til I find it again- it's amazing how they seem to vanish from a 6" drop.
Tighten til snug, but don't over tighten, as it can crack the ring or distort the shape, then the cover doesn't screw on properly.
Add a bag to your port and you've got a handy stow-away.
Thanks for the help-- sounds like you've done this a bunch-- will let you know if I have any additional questions!
 
Thread starter #9
A mark with a Sharpie should get you close enough, or use a ¼" drill to mark the gelcoat, then a tiny bit to keep the final ⅛" bit centered.

When I installed The Ultimate Port, I was surprised to find how thin the fiberglass was. Especially considering the occasional "insult" when stepping :cool:, slipping :confused:, jumping :oops: or falling :eek: into the cockpit. ('Course a bad trailer bed can punch the floor from the other side, and make bad spider-cracks, or, in one of my (now 5) "seasoned" Sunfish, a complete fracture:eek:. (Allowing rainwater to gradually seep into the inside).

The piece I removed was also not that "bendy" (for as thin as it was). This was as far as I would bend this 6"x14" piece, before having a fracture. If the cockpit is the same thickness as the deck or hull, I'd treat every damaged area as bigger than it appears.

(I may have time today to "mike" the deck, then later, "mike" the stored cutout piece). I've stored the piece, as someday, I'll use it in a repair as a "backup piece".

View attachment 26211


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Thanks for your help! Will let you know if I have any complications or more questions!
 
Thread starter #10
That's a tight area to work in. If you want to do machine screws, I would drill a 1/8 inch starter hole, and then put in one #8 screw to hold the port in place, using the drill to drive it. It will be snug. Or drill the hole one size larger. Drill another hole and put in a screw. Drill the rest of the holes. Then remove the port and screws and lay down your sealant. Reinstall the port and snug down the screws.

There is a sweet spot to getting screws that are long enough to get the stop nut started, but not so long as a socket won't fit over then. We keep a deep socket on hand just for those screws.

Or use stainless wood screws or pop rivets. Probably a better approach if the port is small. Wood screws will scrape unsuspecting arms and hands.
Sounds good-- Thanks for your help! Will let you know if I have any more questions....
 
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