Advice on boat repair

[Ellensburg]

Recently bought a boat and I have been working on getting it ready for crabbing/fishing. Everything works great and no major issues yet. I want to fix this area by the plug, before it becomes a bigger issue. Has anyone had any luck with fixing damage like this? Any advice is appreciated.

[jamesfromseattle]

Something like a West System 105k kit maybe? I've used that sort of kit for smaller patches on a fiberglass hole, but not entirely sure how it would work on the corner like that.

[hawksfan75]

With that much corrosion and it looks like the scrape has gotten beyond the gel coat, I'd be concerned about water intrusion into the transom. Have you checked for soft spots and such? If everything is dry, go ahead and try to re gelcoat, but you might need to do some fiberglass work there too.

Not an expert by any means, so if I'm boss, consider me already scolded

[Ellensburg]

With that much corrosion and it looks like the scrape has gotten beyond the gel coat, I'd be concerned about water intrusion into the transom. Have you checked for soft spots and such? If everything is dry, go ahead and try to re gelcoat, but you might need to do some fiberglass work there too.

Not an expert by any means, so if I'm boss, consider me already scolded

i think thats just corrosion from the plug area.

It is still very hard and no soft spots. I know it would cost me $1,000 to take it in and have a pro do it, and I don't think its all that bad. I want to put on an epoxy or something before gel coating. Any other advice guys?

[Encore 280]

Sand it with an electric sander then a couple layers of resin and cloth or mat and call it good.

[elk247]

Spash zone. A marine two part epoxy. It works on steel, aluminum, and fiberglass.

[Skillet]

Warning - this is JUST AN OPINION.  Happens to be mine.  Use whatever you find after this warning at your own risk:

Take the drain plug fitting out.  Check around it for soft material, especially above the plug cutout towards the top of the transom. If none, you're in a lot better shape than I think you are.  If soft wood around the drain plug... just put it back in and put a for sale sign on it. 

If no soft material around drain plug, sand down the damaged area until you only hit good, solid dry wood (assuming this is a plywood transom under that glass).  Trying to fix a wet transom is like trying to put a bandaid on underwater.

Remove any wax on the gelcoat in the area.  Sand off the gelcoat, but not through the glass, about 2" out from the edge of the area you removed the glass from.  It is basically a border for the repair to adhere to and an area you can fair out.  Use a heavy grit (50-60) with your DA or by hand.  A light touch here is needed.  It needs to be scuffed up good, but again - not through the glass.  I like to define the border of the sanded area with duct tape.  It will help with fairing it out later.

Cut a piece of heavy stitchmat that matches the repair area out to about 1" of the edge of the scuffed area.  You'll need the other inch of scuffed area to fair into.  It looks like you'll have some complex curves, so you may need to cut darts into the material to get it all to lay flat.  Once you've got the stitchmat cut to shape, use a light shot of spray adhesive on the backside and stick in in place on the hull.  Too much spray adhesive will start to wet out the mat on the back, so go light with it. It is really important to get the mat perfectly flat on the hull - no bumps, bubbles or folds where the mat is not touching the hull. 

I like to use Research Resin or MAS epoxy for this type of repair.  ALWAYS wear gloves and unless you have a very well ventilated area, wear a respirator when using epoxy - it has nasty vapors and is really bad for you if you get it all over your skin.  Mix up your first batch and completely wet out the stitchmat.  I can't emphasize enough how important it is to completely soak the stitchmat... air bubbles will haunt you forever in there.  I like to use some specialized tools for this, but you can do a repair this size effectively by taking a 3" chip brush and cutting the bristles down to stiffen them up.  Then you can force the epoxy through the mat and tap out the bubbles with it. 

As soon as the epoxy sets (anywhere from 3-8 hours, depending on which hardener you used, temp and humidity) it will be dry to the touch.  The edge of the stitchmat is going to be proud from the hull.  You can take your DA and lightly sand the edges to begin to fair it back into the hull.  Get it close, but don't sand too much and sand through the glass left behind after you removed the gelcoat.

Mix up your next small batch with pigment to match the hull, some milled fibers or cabosil and glass microbeads.  Don't skimp on the microbeads.  You want the epoxy to have a frosting like weight and texture, and not sag after application.  If you got your mix right, the second coat will cover the texture of the stitchmat.  Fair this second coat out to the edge of the sanded area.  After it sets hard (overnight is usually good enough), lightly sand it with wet/dry sandpaper to find any low spots.  If you are good with it, finish it off with a good wet sanding and go boating.  If not, you may need to rough it up and apply a third and final coat of pigmented epoxy.  Lots of microbeads again.  Fair it out, wet sand,  recut your transom plug hole, and off you go.

Again, this is JUST AN OPINION, not a prescription for your specific situation.  I made a lot of mistakes when  I first got started with FG repair, and a lot of them are really hard to describe.  There's a lot of "feel" involved in mixing the microbeads and cabosil in.  I'd practice on a piece of plywood to start...

Good luck.

[RadSav]

I would get the boat out of the weather and drill holes in a half moon every few inches from the damage until I got to clean unstained wood.  I would then inject Boracare or similar into each hole.  Too much is just about perfect!  Then wait a good 20-30 days to make sure it is completely dry.  Only then would I start working on the glass.  I agree with Skillet - if you find soft wood above the drain plug you might want to think about putting her down.

[Smokepole]

Skillet, it sounds like you have repaired a boat or two before.  I recently made a repair using West Systems epoxy.  Didn't turn out as good as I wanted, but the repair will last longer than the boat.  I agree you might want to do a test run.  I let the epoxy stiffen up just a tad so it would't sag.  It is definitely an art.  Not sure if I did it by the book, but it worked. 

[jeepster]

I do this for a living

Get out an angle grinder with a sanding disc and grind out the affected area.

You want to find out the affected area plus two inches or so beveling it as you go.

Example, if it's a 2x6 inch area, you would grind out 4x8, with the bevel only as deep as the deepest boo-boo

Using epoxy on polyester (what 99.9% of fiberglass boats are made out of) doesn't really work because of a chemical incompatibility. It might work for a while, but you'd have to eventually do it again.

Get some polyester resin, milled fiber, and or silica thickener and make a putty, patch with the putty, sand till its smooth, and then gel coat over it.

Make sure to have a surfacing agent in your gel coat. Polyester resin needs to be inhibited from the air in order to cure properly.

My advice, google "fiberglass supply Burlington Washington"

They are the absolute best when it comes to getting you what you need. Explain the problem, they have a great online store and ship anywhere

[RadSav]

I do this for a living

I learned from an old boat builder who also did repair.  But that was more than 30 years ago.  We repaired a lot of Dorys with rot issues during my classes.  Are you thinking the rot is not bad, or are you just expecting to grind the rot out expecting it to be just a surface issue?  We usually worried more about the rot issues than the glass damage.  Do you not worry much about that and leave untreated if you grind into hard wood?

Not trying to disagree with the expert.  Just trying to understand how you guys are doing things nowadays.  Poor day is a day you don't learn something!

[Seahawk12]

Here is a thread for a similar problem I dealt with.
I haven't posted the final yet because I haven't applied the gel coat yet.
http://hunting-washington.com/smf/index.php/topic,172977.msg2293738.html#msg2293738

[Ellensburg]

Thanks for all the replies.

I think the picture makes it look worse than it is. It is only about 3 inches long and never more than a milimeter deep. There are no soft spots. Sounds like I can sand it, fill it, and re-coat it. Probably take all day but i'll post updates once i do it.

[RadSav]

Thanks for all the replies.

I think the picture makes it look worse than it is. It is only about 3 inches long and never more than a milimeter deep. There are no soft spots. Sounds like I can sand it, fill it, and re-coat it. Probably take all day but i'll post updates once i do it.

I was thinking it was more extensive then that. So I guess I'm just a doom and gloom worry wart!  Do you know how long it has been that way?  Sounds like Jeepster was right on the money with the resin, milled fiber and silica advise.  Good luck

[Ellensburg]

I do this for a living

Get out an angle grinder with a sanding disc and grind out the affected area.

You want to find out the affected area plus two inches or so beveling it as you go.

Example, if it's a 2x6 inch area, you would grind out 4x8, with the bevel only as deep as the deepest boo-boo

Using epoxy on polyester (what 99.9% of fiberglass boats are made out of) doesn't really work because of a chemical incompatibility. It might work for a while, but you'd have to eventually do it again.

Get some polyester resin, milled fiber, and or silica thickener and make a putty, patch with the putty, sand till its smooth, and then gel coat over it.

Make sure to have a surfacing agent in your gel coat. Polyester resin needs to be inhibited from the air in order to cure properly.

My advice, google "fiberglass supply Burlington Washington"

They are the absolute best when it comes to getting you what you need. Explain the problem, they have a great online store and ship anywhere

I met up with Jason at the Burlington fiberglass supply and he was the most helpful guy ever. I got all the supplies needed for 70 bucks. I will post pictures after I complete the work