The Tao of Fiberglass Repair

[Seadogg]

Well, I've put it off long enough. Now is the time!

This weekend I plan on doing some glass work on my boat. I bought "First Step" last August. Her previous owner had done a LOT of modifications. She has three small thru-hulls (sealed up)and one fairly large thru-hull that is connected to a seacock. I'm planning on removing and glassing over the three smaller ones.

My plan is this:

These are gonna be 1 inch holes, all below the water line. I'll be using epoxy and cloth and working from the inside. After removing the thru-hulls and sanding and beveling, I plan on making a "puck" to insert in the 1 inch hole holding it in place on the outside with a plastic sheet and tape. Then I'll do a fill with epoxy and silica, then begin applying the cloth and building up.

When done, I should only have a 1 inch or so spot to paint on the hull.

What do you think? Any suggestions? Tips? Warnings?

I'll post pics of the progress as I go.

Fair winds,

Nick

[CharlieJ]

You will need glass on the outside also. DO NOT rely on just the puck holding- if it fails your boat goes down. Nothing wrong with using a puck as a filler to set the glass against on both sides, but you need to taper each side, then back fiill with glass out past the hole.

Here's a link to an article in the Gougeon's EpoxyWorks magazine on how to repair holes. Click on "Boat Repair & Restoration" then when that comes up, click on "Repairing machined holes in fiberglass"

http://www.epoxyworks.com/indexprojects.html

By the way- I did the same thing on the last two boats I had. Tehani had SEVEN holes below the waterline when we got her and only three of them even had valves- the rest were just pipes glassed to the hull. She now has none, zero, nada, zip.  ;D

[Seadogg]

Thanks, Charlie!

Quick question:  When doing this from both sides, after beveling, cleaning etc.,do you glass one side first (say the inside) and then the outside?  Or try to do both the inside and outside at the same time?

Thanks,

Nick

[AdriftAtSea]

I would recommend that the primary glassing be done from the outside...as the water pressure will be helping to hold the repair in place, rather than working against the repair...but that's just me.  Also, properly cleaning the surface before sanding the material is very important.  Sanding can imbed certain impurities that can interfere with the proper bonding of the repair, like silicone.

It is probably easier to glass one side and then glass the other.  Pushing on both sides of the repair is a good way to prevent the laminate from bedding properly on one side or the other...  Also, I generally recommend going largest patch to smallest, that way, if you are fairing the repair, the sanding can't cut through the largest layer of glass, and any sanding that hits glass will remove a bit from the edges of each layer, rather than putting  a hole in the outermost layer.

[Seadogg]

Largest patch to smallest?  That's interesting.  I haven't heard that before.  I have seen it in the West System document but always wondered if that was a perception thing. 

[AdriftAtSea]

Well, fiberglass gets its strength from the long, uninterrupted fibers...and when you do a repair, the glass is often sanded a bit from fairing the repair.  If you go from the smallest (deepest in) to the largest, the sanding will damage the largest patch, possibly even sanding a hole through it...greatly weakening the repaired area. 

If you go from the largest patch, being deepest, to the smallest, then the sanding is most likely going to damage the ends of the glass strands, which doesn't really affect the strength of the repaired area, as your just trimming the glass fibers to length, nut cutting them in half.

[Seadogg]

Ah...I'm beginning to see the light!   ;D

Another thing is this; a couple of these thru-hulls are almost directly on the bottom.  Seems this is going to be a little difficult getting things to set without sagging.

Any suggestions?

[CharlieJ]

A. Use as little resin as possible, as long as all the threads of glass are wet out. What you want is totally wet glass, with NO excess. Hard to do but do-able.

B. You can lay a piece of plastic such as visqueen over the glass and squeegee it down getting a smooth. But then you need to grind that to get tooth, so I'd only do it on the final layers.

Actually you really don't get a lot of sag if there is little or no excess resin. Just lay in the first layer, then let that kick till it's tacky, THEN lay in the next few layers. Then go inside and do tha same.

I usually do 3 - 4 layers on one side, then go to the other, alternating til the thickness is built. Then sand smooth and roll on a final thin smooth seal coat of epoxy.

[Seadogg]

Thanks, Charlie.

And you agree with Adrift At Sea on working larger to smaller?

[AdriftAtSea]

You can use a slightly thickened epoxy... might want to get a recent issue of Practical Boat Owner, which had a very good article on fiberglass repairs, as presented by West Epoxy.  I'd also check out West Epoxy's website:  http://www.westsystem.com/

Polyethylene plastic is also good to use, as epoxy doesn't stick to it very well, and it might be easier to find than visqueen sheeting.

I hope this helps.

BTW, the page you want is located at http://www.epoxyworks.com/21/practical.html 

darn frame-based websites don't let you book mark pages properly.

[Seadogg]

I really appreciate al the help from you guys!!

Obviously, I'm a little nervous about my first glass project.

[AdriftAtSea]

Good luck...post pix and let us know if you run into any snags...we'll help where we can. :D

[CharlieJ]

absolutely and for the reasons he gave.

Adriftatsea- that link doesn't work- that's why I gave him the main page and told him where to click. Don't know WHY it won't go there directly, but it doesn't seem to want to.

And polyethylene plastic is what I meant- called it visqueen for to many years I guess ;D

[AdriftAtSea]

The link does work, if I hadn't typed a invisible character after the end... ugh  Try this: 

http://www.epoxyworks.com/21/practical.html

:D

[CharlieJ]

AH- good- that's the article I pointed out to him. Really good info in there. In fact, Epoxyworks is a really good read for anyone messing with the stuff.

[Seadogg]

As you may have read in some of my other posts, the PO of my boat, "First Step", made many modifications--many of which have left me scratching my head.   Of the numerous thru-hulls, there is on on the lower starboard side of the transom that's connected to a seacock.  The seacock has a "T" fitting with one hose going up to a thru-hull at the top of the transom and another that APPEARED to be going into the swing keel trunk.

Well, last night, I did some in-depth checking and made a discovery.

This whole contraption is the plumbing for a marine head that he must have had on the boat at one time!  The hose that I thought was going into the keel trunk is actually going into the bilge area and ends where the head was.

Since we use a porta-potti on board, this connection is superfluous.  At least I now know that it can be removed without causing any issues.  Of course, this will be a major glassing project and--as the connection is good and there are no leaks--I'll hold off until towards the end of the sailing season to remedy it.

It'll be a bit of bugger as the seacock is located quite low on the transom and it'll take a little ingenuity to figure out how to bevel the area for the patch.  I'll do this after I do the three other little thru-hulls and gain some experience.

Mystery solved!!

Fair winds,

Nick

[AdriftAtSea]

And again, that is one reason I really hate frame-based websites.  You can't bookmark anything worth a darn.  :D

Seadogg-  How is the great glassing project going???

[Seadogg]

Welllll..... weather and some family obligations have gotten in the way at the moment.  I'm hoping to be able to spend an entire day working on this.  Or, at least, have the day available if need be.

Of course, there's always the dilemma of, "It's a nice day!  Do I spend it working on the boat or do I go sailing?!!"  ;D

Also, I finally discovered the answer to one of my boats mysteries in another post here.  Which, of course, means another project.

Soon ..... I'll keep you all informed.

Fair winds,

Nick

[Seadogg]

The prep continues!

I've been getting LOTS of great advice from the sailing community.  Charlie, Adrift, Dave, and a lot of other folks have been kind enough to share their experiences with me so I don't have to reinvent the wheel!

I've been practicing with my epoxy and fiberglass cloth and now feel pretty comfortable with the procedure.

Soooo...I'm hoping to remove the first thru-hull tonight, clean up the area, sand it to a nice 12-1 bevel (wearing all the right gear, of course!) and get ready to do my first glass repair.

I've chosen the thru-hull on the very bottom of the boat as my first fix.  :o

I'll be posting pics and let everyone knows how it goes.

I'm VERY much looking forward to having a solid hull!!  :)

Fair winds,

Nick

[AdriftAtSea]

BTW, the Tyvek Bunny Suit is important if you don't want to spend the next week itching.  :D