Enlarging a 7/8" hole to 1"?

[Wade Lippman]

I bought a used fiberglass sailboat. It has a 7/8" drain plug that is missing the stopper. I can't find any 7/8" plugs, so I am going to replace it with a 1" plug. That obviously requires me to enlarge the existing hole. On a drill press that would be easy, but getting the sailboat on my drill press would be tough.

I have two ideas...
1) Draw a 1" circle over the existing hole and enlarge it with a multitool. My experience is that multitools are not particularly precise, so I m reluctant to do this.
2) I have a cove router bit that has a full diameter of 1". Put in a drill, it should self center in the 7/8" hole and then enlarge it to 1". Or maybe not.

Comments or other ideas would be appreciated.

Or, I could fiberglass over the existing hole and put a new one elsewhere. I have a brad point carbide 1" drill.

[Lee Schierer]

Make a 7/8 dowel and drill a 1/4" hole on center inton one end. Place the dowel in the existing hole. Then enlarge the hole wit a 1" hole saw using the 1/4" hole as a guide to enlarge the existing hole.

Or just buy this 7/8" plug: https://www.amazon.com/Attwood-Brass-Handle-T-Handle-Drain/dp/B0000AZAOW/ref=sr_1_5?ie=UTF8&qid=1546451969&sr=8-5&keywords=boat+drain+plug

[Dan Friedrichs]

Step drill bit: https://www.amazon.com/HUELE-Titanium-Drill-Speed-Steel/dp/B06Y25PFMZ/ref=asc_df_B06Y25PFMZ/

[Mike Hollingsworth]

Cut a 1" hole in a board with the brad point bit. Put it over the hole and use it as a guide.

[daryl moses]

Turn down the 1" plug to 7/8".

[Bruce Page]

Look again for drain plugs. I saw lots of options when I googled 7/8" drain plug.

[Wade Lippman]

Look again for drain plugs. I saw lots of options when I googled 7/8" drain plug.

Yes, lots come up when you google 7/8" drain plug; sadly nothing that comes up actually is.
This is what I ordered. https://www.amazon.com/gp/product/B00K3U2GY0/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

A lot of interesting suggestions to enlarge the hole; maybe the step drill is best, though the template is cheaper.

[Tom M King]

How thick is it where the hole needs to go? What type of plug-screw in, t-handle screw type, or lever handle. What type of boat? No sleeve for the plug? I might have one.

[Wade Lippman]

How thick is it where the hole needs to go? What type of plug-screw in, t-handle screw type, or lever handle. What type of boat? No sleeve for the plug? I might have one.

Very thin; certainly no more than 1/16". The old one is similar to the link I posted.

[Mike Cutler]

Wade

Defender Marine is only 3 miles from where I work. They're one of the largest Marine supply companies in the US and world. If you give me a picture of the plug area, the hull name type, along with the dimension, I'll stop by Defender Marine for you.
I'd hate to see you drill a hole in a boat hull you don't need to.

[Tom M King]

So the female threaded part is still there, and you just need a replacement plug? What type of boat is it? I used to have a small sailboat business, and have a lot of leftover parts.

[Wade Lippman]

400109400110

The above are the front and back of the drain from the Precision 15K. It was missing the plug when I got it, but I presume it is a tube with two nubs on the end for engaging the drain.
It is not in good condition, so I would prefer to replace it rather than just get a plug for it, but a 7/8" would be great, rather than drilling for a 1".

Humorously....
As I typed this, it occurred to me that I should check Precision's website to see if they sell parts. They say they sell the drain for $7 plus shipping. I will call them tomorrow and see if it is 7/8". Maybe.
It is my fourth sailboat, but the first from a company that was still in business; so it took me a while to think of this.

[Prashun Patel]

Drill a 7/8” plug with a hole saw and then switch to a 1” hole saw. Thread the 7/8” plug onto the pilot bit and wrap with a couple layers of blue tape to make up most of the kerf.


I have done this and it makes a passable hole.

[Tom M King]

Glad you found a source. I don't know who makes Precision's hardware. There aren't but so many manufacturers. Simplest to get one from them. I know I don't have any of them.

such as Ronstan: https://www.ronstan.com/marine/range.asp?RnID=125 edited to correct wrong link

[Perry Hilbert Jr]

I had a bad experience with electricity as a kid and avoid working on anything electrical as much as possible. BUT, I would rather try to connect 440 volts to something than ruin a boat. I would find a way to make a plug rather than drill a hole.

[Alan Rutherford]

I had a bad experience with electricity as a kid and avoid working on anything electrical as much as possible. BUT, I would rather try to connect 440 volts to something than ruin a boat. I would find a way to make a plug rather than drill a hole. It's part of the joy of boat ownership. You know how they say owning a sailboat is like sitting in a cold shower tearing up $20 bills ($100 for big sailboats)? A lot of those $20 (or $100) bills go for stuff that attaches to the boat and you gotta drill holes to do that. He's getting off easy. Only one hole, it's already there, and only part of a $20 bill.

Can you guess what happens when you drill a hole in the bottom of a 27' fiberglass sailboat to install a speedometer sensor while the boat is sitting in the water? You'd think the water would squirt up to the cabin roof and get all over everything and sink the boat but it doesn't. The water inside can only squirt as high as the water outside the boat. If the hole is say 10" below the waterline it can squirt 10" high at most. If you're ready to fish the lead wire for the sensor through the hole you only get a few gallons of water in the boat. The other lesson I learned that time was if you plug too many extension cords together you burn out your drill. That was before cordless. Fortunately I finished the hole first. But that's getting off the subject.

I've drilled a lot of holes in boats, torn up a lot of bills doing it, and it was very rewarding some of the time. Can't say I'm anxious to do it again though.

[Bill Dufour]

Make the 7/8 plug with a center hole for the hole saw pilot bit. Only thing is taper the plug so it does not push through the existing hole and lose register while drilling. Not the plug does not have to very accurate as long as it bears on at least three points more or less evenly spaced. Four may be easier to make on a jointer, table saw or bandsaw.
Bill

[Lee DeRaud]

Step drill bit: https://www.amazon.com/HUELE-Titanium-Drill-Speed-Steel/dp/B06Y25PFMZ/ref=asc_df_B06Y25PFMZ/That's certainly the right tool for the job. $9 sounds pretty cheap given that the alternative is bugger up the hull, buy the stuff to do a fiberglass repair, and then drill a new 1" hole.

[lowell holmes]

If the boat is a keel boat that stays in a slip, take it to a yard where they can haul it out for you.
I am speaking from experience having owned a 34 foot sloop. It had an auxiliary motor in it and it developed a leak at the shaft hole.

[Roger Feeley]

I've run up against this a number of times. Here's what I do.

Find a hole saw that produces a 7/8" plug and drill out a few plugs.
Put the 1" hole saw on your drill using the same pilot bit.
put the plugs onto the pilot bit as needed so you now have a 7/8" pilot
Drill a bit from both sides to avoid tearout then drill through using the pilot.

[Alan Rutherford]

This is an incredible amount of angst over what should be a small problem. There must be a million small boat drain-plug fittings. First he needs the replacement fitting, then he can find a way to attach it to the boat, which should not be difficult.

What he should NOT do is make a tapered plug for the existing fitting or the hole it was in. The plug for the hole should screw in or twist-lock. Although drains are normally above the waterline, things happen and you don't want the plug to fall out.

Note the flange and ears on the old fitting. The old bolt holes will be a bigger problem than the drain hole if the new ones don't match, especially if he's also drilling the drain hole bigger. Of course it's possible the old fitting was just held in by caulk but that's not a good idea.

Assuming he finds a new fitting and it requires a bigger hole, the hole can be enlarged with a rasp. If it's less than perfect, any gaps can be filled with the caulking the whole thing should be bedded in when it is bolted in place. In fact, it's better if there is enough gap between the hole and fitting to allow caulking to push into that gap, rather than a precise fit between fiberglass and nylon.

[Tom M King]

If the boat is a keel boat that stays in a slip, take it to a yard where they can haul it out for you.
I am speaking from experience having owned a 34 foot sloop. It had an auxiliary motor in it and it developed a leak at the shaft hole.

That's why they say "Leave it in the water, and it will get wet". This is about a Precision 15 plug. No need for a yard to haul it, or most of the other advice.

[James Waldron]

If the boat is a keel boat that stays in a slip, take it to a yard where they can haul it out for you.
I am speaking from experience having owned a 34 foot sloop. It had an auxiliary motor in it and it developed a leak at the shaft hole.

Reading your posts about your various disasters on all manner of subjects, I think I'll pass on sailing on your boat, Lowell. :D Wouldn't want to get my Topsiders wet!!!! :eek:

[Jim Koepke]

Reading this thread has been interesting for me. The highway to town from my home runs along the Columbia River. During the past month or so there has been a boat anchored in the middle one of the navigable inlets off the river. At first it had a blue tarp under it and up the sides. Recently the tarp was removed. When traveling to town with the wife we would wonder about the boat, why there wasn't any name on it and other things.

A few days ago when we were driving into town, there was only a little bit of the boat above water.

This gives me great pause in thinking about a quick fix for any boat related repairs.

jtk

[lowell holmes]

If you go offshore in a sloop, you will surely get your feet wet. :)
OBTW, we crossed the Gulf of Mexico both North-South and East-West.
We crossed the Gulf four times.

[Wade Lippman]

While I was working on a winter boat cover today, a professional fiberglass repairer happened by.
He said he would use a step drill to enlarge the hole, except that I can't enlarge the hole. It is too close to the bottom and I don't have and extra 1/16" there.
He would hold a 1" hole saw at an angle, using the bottom of the existing hole as a guide to start it, and cut a new 1" hole; so it would be the same as the old hole at the bottom and 1/8" higher at the top. However, he assured me he could find a 7/8" drain plug.

He also thought the framework for the boat cover I was building was the dumbest thing he had ever seen; why didn't I just spend $100 and have it shrink wrapped. Well, the lumber was $20 and the tarp was $20, and I can use it for many years. Sure, but what about the hours I put into it. I tried to explain it was hobby and I enjoyed building things; but he just walked away shaking his head. The unretired will never understand.

[Jim Koepke]

The unretired will never understand.

People often wonder why an hour of my time is spent on fixing something that could be replaced for a low price. They never seem to realize it would take me at least an hour to make a trip into town and back.

Being retired and living over ten miles from the nearest store changes the way you live.

jtk

[Tom M King]

Here you go. Looks like the original is so hard to find because the design was updated. A google search for "drain plug requires 7/8" installation hole" found it.

http://www.apsltd.com/rwo-screw-in-drain-plug-complete-assy.html?fee=5&fep=27264&utm_source=Google+Shopping&utm_medium=cpc&utm_campaign=Product&gclid=Cj0KCQiApbzhBRDKARIsAIvZue8FfCHMCCYdumOgmh-cWwVHLx1r1HAF8NalKNpsvTzBw2jJyiVlbaAaAqEREALw_wcB

edited to add: I was thinking it was the same inner hull plug that Lasers used, so a google search for "laser inner hull plug" turned up this:

http://www.apsltd.com/rwo-1-4-turn-drain-plug-complete-assy.html

[Osvaldo Cristo]

I bought a used fiberglass sailboat. It has a 7/8" drain plug that is missing the stopper. I can't find any 7/8" plugs, so I am going to replace it with a 1" plug. That obviously requires me to enlarge the existing hole. On a drill press that would be easy, but getting the sailboat on my drill press would be tough.

I have two ideas...
1) Draw a 1" circle over the existing hole and enlarge it with a multitool. My experience is that multitools are not particularly precise, so I m reluctant to do this.
2) I have a cove router bit that has a full diameter of 1". Put in a drill, it should self center in the 7/8" hole and then enlarge it to 1". Or maybe not.

Comments or other ideas would be appreciated.

Or, I could fiberglass over the existing hole and put a new one elsewhere. I have a brad point carbide 1" drill.

Yours is the classical application for step bit if it is in a flat surface. I think the thickness of the material to be drilled is not bigger than the "step" of the bit...

Good luck in your project!

[Tom M King]

Reading is at such a premium here.

This is funny. We have two Lasers here. I went out, and checked, and that white, bayonet version is indeed the inner hull plug. Both of ours could stand to be replaced. Thanks for posting the original thread. I'm ordering a couple of the newer design, and it might have saved us some missed sailing time this Spring. I'm sure I would have overlooked them otherwise.

[Wade Lippman]

Here you go. Looks like the original is so hard to find because the design was updated. A google search for "drain plug requires 7/8" installation hole" found it.

http://www.apsltd.com/rwo-screw-in-drain-plug-complete-assy.html?fee=5&fep=27264&utm_source=Google+Shopping&utm_medium=cpc&utm_campaign=Product&gclid=Cj0KCQiApbzhBRDKARIsAIvZue8FfCHMCCYdumOgmh-cWwVHLx1r1HAF8NalKNpsvTzBw2jJyiVlbaAaAqEREALw_wcB

edited to add: I was thinking it was the same inner hull plug that Lasers used, so a google search for "laser inner hull plug" turned up this:

http://www.apsltd.com/rwo-1-4-turn-drain-plug-complete-assy.html

That's incredible! I googled on "drain plug 3/4"" and got nothing.
Thanks.

And thanks all for your help.

[Tom M King]

I knew it either had to be still available, or had been replaced with something that would work. I was in the small sailboat business for 7 years, back in its heyday in the '80's. I probably have some somewhere, but would be really hard to find. Jetskiis took the market for small performance sailboats. I tried to sell the business for a couple of years, but that whole market had tanked. I was lucky enough to have it wiped out by the largest tornado to ever hit North Carolina, and didn't reinvest the insurance check in the boat business.

[Bert Kemp]

this should work
https://www.amazon.com/Five-Oceans-Marine-Rubber-FO-2210-M2/dp/B072HJHFQ9/ref=asc_df_B072HJHFQ9/?tag=hyprod-20&linkCode=df0&hvadid=309819417245&hvpos=1o1&hvnetw=g&hvrand=14706040701972460260&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9030113&hvtargid=pla-570473710730&psc=1&tag=&ref=&adgrpid=62061529859&hvpone=&hvptwo=&hvadid=309819417245&hvpos=1o1&hvnetw=g&hvrand=14706040701972460260&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9030113&hvtargid=pla-570473710730

[James Waldron]

If you go offshore in a sloop, you will surely get your feet wet. :)
OBTW, we crossed the Gulf of Mexico both North-South and East-West.
We crossed the Gulf four times.

Back in the day, I was a bowman. My rule for offshore racing was to run foredecks only for owners who brought their (pretty) daughters along. Now-a-days, I'm so old that I only go for rides on boats, but only ones with owners who bring their (pretty) mothers along.

[Alan Rutherford]

Back in the day, I was a bowman. My rule for offshore racing was to run foredecks only for owners who brought their (pretty) daughters along. Now-a-days, I'm so old that I only go for rides on boats, but only ones with owners who bring their (pretty) mothers along. You couldn't have crewed on my boat. No daughter. There were some women, though. Except for a token male, the crew on my Cal 40 was almost all women. Maybe you could have bribed your way aboard. Now that I think about it, I should have put that token male position out for bids.

That was 35+ years ago and even then the Cal 40 was getting outdated for serious racing but we had a good time. It's harder than you might think for competent female sailors to find a boat to crew on, largely because so many of the men who own boats also have wives. There's also the reality that when you need a foredeck ape, men are more likely than women to have the brawn. I had a good crew and what they lacked in beef they made up in teamwork and camaraderie.

I sold the boat a long time ago and no longer live in that part of the country, but I understand some of the women who met on my boat are still in touch. I know a few have continued to race and cruise and at least one has since sailed around the world.

I've probably sailed 20,000 miles on the ocean and many more in the PNW but you move on...

[James Waldron]

You couldn't have crewed on my boat. No daughter. There were some women, though. Except for a token male, the crew on my Cal 40 was almost all women. Maybe you could have bribed your way aboard. Now that I think about it, I should have put that token male position out for bids.

That was 35+ years ago and even then the Cal 40 was getting outdated for serious racing but we had a good time. It's harder than you might think for competent female sailors to find a boat to crew on, largely because so many of the men who own boats also have wives. There's also the reality that when you need a foredeck ape, men are more likely than women to have the brawn. I had a good crew and what they lacked in beef they made up in teamwork and camaraderie.

I sold the boat a long time ago and no longer live in that part of the country, but I understand some of the women who met on my boat are still in touch. I know a few have continued to race and cruise and at least one has since sailed around the world.

I've probably sailed 20,000 miles on the ocean and many more in the PNW but you move on...

Deck apes work aft of the mast. Any owner who has a "foredeck ape" has to live with spinnaker wraps and halyards up the mast. Better to get a proper bowman.

And for those who don't sail, you should look into it. Bowmen often serve as "boat nannies" as the modern terminology goes, and are some of the most proficient varnishers extant. If you find one who'll let you watch, you can learn some wonderful technique.

[Alan Rutherford]

Deck apes work aft of the mast. Any owner who has a "foredeck ape" has to live with spinnaker wraps and halyards up the mast. Better to get a proper bowman. And for those who don't sail, you should look into it. Bowmen often serve as "boat nannies" as the modern terminology goes, and are some of the most proficient varnishers extant. If you find one who'll let you watch, you can learn some wonderful technique. A good crew is the most valuable thing on the boat. Setting or jibing the spinnaker in strong winds takes skill and teamwork and everyone on board can be proud when it works the way it should.

What I learned about varnishing, though, is that if you're not going to make a fetish out of teak, the best thing to do is not much. You can get away with that with teak. I once owned a wooden 1940's 40-foot power boat that had a varnish skin like nothing I have ever seen since or been able to reproduce. It was beautiful but I didn't keep it long and went back to fiberglass and teak.

[Roger Feeley]

I live in the DC area. I don't own a boat but know a guy who does. He told me about his arrangement that sounded pretty good to me. He has his boat at a marina where it's stored in a multi-level warehouse. When he wants to take out the boat, he gives them at least a couple of hours. They take a fork lift and put his boat in the water, gas it up and have the cover off so it's ready to do. They will clean and maintain it. I think he pays about $500 a month during the season for a spot very convenient to downtown DC. The basic services above are included. The marina also offers repairs which he says are competitive.

If I had a boat, this plan seems pretty good to me. You know how much you are going to pay and are relieved of the drudgery of spending the your time off cleaning the boat. You go to the marina, hop in and go.

The guy that told me about this cleans our pool so he isn't crazy rich. I think he does ok. He doesn't spend a lot of money on other things. The boat is his and his families primary pleasure. I remember when I was a young sprout, a friend of my parents were out every weekend in their Airstream. Their house was really modest because they dumped all their money into Airstream caravans and other travel.