Help making fiberglass tube

Can someone give me detailed instructions on how to make a fiberglass tube? I intend to use it to create new scuppers forward of my existing ones because water tends to pool up there. I'm thinking maybe 1 1/2" or so outside diameter, about 4" long. I'll make a hole through both inside and outside topsides and epoxy in the tube. I have epoxy, but never used cloth. What weight will I need? Can I use a piece of pvc pipe for a form and how do I get it to release? I know this is elementary stuff, but gotta start somewhere.

You can buy books and DVDs to learn how to work with fiberglass. Nobody can post enough on a web forum to make a beginner into an expert.


Also, are you sure that's the best way to accomplish your goal? Could you just use thruhull fittings and hose instead? Or something else?

Whenever needed, fiberglass tubing was too labor intensive to bother with unless a custom size or shape was necessary. For simple 1.5 diameter in varoius guages, I use E-Bay or for small length cut offs, a local salvage.

Fiberglass Round Tube 1 5" OD x 1 25" ID 20 Feet | eBay

This tutorial is for making a carbon fiber spar/mast but it will show you some f the basics.

Carbon Fiber Spar - Page 1 | Bateau2

If possible get a fiberglass sleeve(s). Basalt sleeves work well too.

2 Braided Fiberglass Biaxial Sleeve in stco | Fibre Glast

You can use a PVC pipe for a mandrel for short pieces. Mold release can be PVA (Poly Vinyl Acetate) or wax. Carnuba car was will work. You'll want multiple coats applied. The biggest challenge will be to get it wrapped tight enough to remove as much trapped air as possible. Heat shrink tubing works well.

The better choice might be to buy some pre=made fiberglass tubing. Great Lakes Skipper and eBay come to mind there. I picked up a 12" piece of 2" for $15 IIRC.

If there is a good boatyard near you, they often sell it by the foot. The yard I use usually keeps 3" to 8" in stock. Often there are scraps <1' lying around.

Ted

mike66 said:

Can someone give me detailed instructions on how to make a fiberglass tube? I intend to use it to create new scuppers forward of my existing ones because water tends to pool up there. I'm thinking maybe 1 1/2" or so outside diameter, about 4" long. I'll make a hole through both inside and outside topsides and epoxy in the tube. I have epoxy, but never used cloth. What weight will I need? Can I use a piece of pvc pipe for a form and how do I get it to release? I know this is elementary stuff, but gotta start somewhere.

Click to expand...

Know exactly what you are trying to do, have spent the last 2 years just trying to figure out how to make the existing, broken ones look better.

I just trimmed my 40 Albin a bit more stern heavy so now the scuppers actually do their job.

The problem is going to be getting any kind of tube flush with the deck level or there will still be standing water turning into a dirt spot.

Because you don't need to shed a lot of water...as the rest of the suppers will shed heavy spray and filling green water....all you need is about a 1/2 inch hole to drain standing water off, correct?

I would think about a 1/2 to 1 inch bronze thru-hull. You just put it in like normal from outside the hull using a good adhesive caulk like 4200 or 5200 . But drill the tail hole from the inside of the caprail so bottom of the hole is slightly below deck level. After test fitting, cut flush on the inside, and either adhesive or epoxy the inner connection.

mike66, check out my album labeled 'Making a New Mast'. I made tubes for adapting the original bronze maststep to an aluminum tube, from the aluminum tube to the masthead, as well as a third piece for the socket of a kayak davit. Look at the pics and, if you need more info, give me a buzz.

Not at all difficult.

McMaster-Carr has a relatively small selection of structural fiberglass tubes (but not the size I needed. Fiberglass tubes for marine exhaust are made by Centek and short lengths are sold online.

The pic below is the socket for the kayak davit, taken yesterday. Lots more work required to better fillet the pieces together and make it pretty enough to paint. It will be bolted to the flybridge enclosure. The davit, under the socket, is laminated Ash and will be coated with epoxy and painted.

Model rocket guys use these all the time...
It's really not worth the effort to build your own unless you need specific sizing.....Not when you can buy a 6" x 1.5" tube for $11..

https://giantleaprocketry.com/products/components_airframes.aspx

It is easy to make a tube with smooth insides. You need a form of some sort. Either a piece of aluminum or stainless steel tube works well, but PVC will work too. Basically you start by spraying the form with 3-4 coats of PVA (polyvinyl alcohol). You can also use unscented hair spray but you will need about 10-12 coats. Once the form is coated cut out the glass fabrics you will need. For a scupper I would use a layer of 1.5 oz mat, 2 layers of 1708 biaxial fabric or 5 layers of 10 oz cloth and a final layer of 1.5 oz mat. Cut each piece of fabric to the length needed and a width that allows it to wrap around the form with about a 1" overlap.

Start fabrication by painting the PVA coated form with unwaxed gel coat. Let the gel coat kick then wet out the first layer of mat on a sheet of cardboard and wrap the wetted out mat around the pattern. Go over the mat with a paint brush or air roller to remove air. Repeat with the cloth fabrics and then the final layer of mat. Let the whole thing cure then either knock the pattern out or cut the tube in half on your band saw and remove the pattern. The whole process will take about two hours. It will be easier and faster if you use polyester resin instead of epoxy.

I have used this method to build mast steps for fiberglass sailing dinghies using a section of mast as the form. It is easier than it sounds.

A couple of pointers. Wear rubber gloves. Wear two pair so you can remove one pair during the layup it the gloves get gunky. I like nitrile gloves.

Thanks to all. I will either buy the pre-made or go with a through-hull. Getting the holes cut for a thru-hull that lies flat on the outside might be a challenge, I'll have to look at it closely. Maybe a couple hundred pounds of ballast will fix it.
TDunn, I will keep your detailed instructions and I thank you.

Would square or oblong tube be better than round, for your purpose? Should be available at plumbing supplies stores in PVC. Without seeing the job, making your own tube sounds a big ask.

Mike,

I think I would do as others have suggested and buy a drain grate from Defender, hose and a through hull. Making the tube seems like too much work. When I needed a new stern tube I bought it from here Nor' Easter Yachts, Inc. - Custom Fiberglass Manufacturing - Milford, CT Not too far from RI and an interesting shop.

Rob

p.s. I was replacing a home made tube!

Use a cardboard tube shmeer the outside with any wax you have , or simply wrap it in aluminum foil.

After the lay up simply sink the cardboard for a day or two.

IF an oval tube is required use epoxy as it cures slower and can be formed after the layup is completed.

Folks that want to make a complex shape can create a plug with blue foam, paint it with a layer of epoxy then lay up what you wish with polly or epoxy.

Old battery acid will remove the foam easily .

KISS

FF said:

Use a cardboard tube shmeer the outside with any wax you have , or simply wrap it in aluminum foil.

After the lay up simply sink the cardboard for a day or two.

IF an oval tube is required use epoxy as it cures slower and can be formed after the layup is completed.

Folks that want to make a complex shape can create a plug with blue foam, paint it with a layer of epoxy then lay up what you wish with polly or epoxy.

Old battery acid will remove the foam easily .

KISS

Click to expand...

Polyester resin will dissolve blue foam.

"Polyester resin will dissolve blue foam."

YUP,

"Folks that want to make a complex shape can create a plug with blue foam, paint it with a layer of EPOXY then lay up what you wish with polly or epoxy."

I have found it is relatively easy to make short lengths of fiberglass tube using PVC pipe as a former. Spray release agent on the pipe, wrap with a turn of overhead projector film held closed with scotch tape, spray that too. Lay up the glass, push the PVC pipe out when cured, and remove the film. Further wraps of glass can be added if additional thickness is required.

It is easier to buy off the shelf, but I have never regretted learning to do stuff like this.

Gasoline and lacquer thinner will dissolve the blue or the white polystyrene foam. Best to remember that both of these have low vapor pressures and burn cheerfully.

Fiberglass tube sources.

The largest mfg of fiberglass tube in USA is 'smith fiberglass'
Smith Fibercast Fiberglass Pipe & Fittings, Composite Pipe
It's used in chemical plants all over the world.
Mcmastercarr also has it in stock and they take cc now too. example....1"x5'$15.00
McMaster-Carr
Also regular marine supply stores , used frequently for exhaust systems .
https://shop.hamiltonmarine.com/ine...searchstore&search[searchfor]=Fiberglass+tube
No need for epoxy in this application unless you don't like the smell of polyester and like to spend a lot of $$ for epoxy.
If you want rigid tube I would use PVC if I could they have threaded fittings.
Also there are special flush thru hull fittings that have a countersink type head, often used by blow boaters to keep hull smooth.

Warren

Plastic or chrome, flush heads with strainers.