My First Backing Patches

shorefun

Well-Known Member
This is my 'practice' hull. It had the major hit on the keel and the scrap to glass on the chine. On the topside the cleat was push down and the combing is broken loose.

This is my first ever fiberglass work. My goal was to put in a backer without putting a hole on the top just to see if I could do it. I will need to do something like this for the bow of my sons sunfish.

As you can see I tried the string pull method. Doing this on the chine suffers from the hull being a compound curve in all directions. So the problem is to limit the wrinkles that will form. You can see I used a manilla folder for the backing. It was stiff enough, but flexible to not kink much when pulled tight. I needed to cut the hole in the middle or the paper would kink from the compound curves. My hope/ goal was the glass would stay below the lines of the hull so I can layer on top without sanding the backing. I have not checked if I met this goal.

It was a sort of complex operation with all the strings. I used twigs so the string would not pull out. I pulled the strings tight and bent them over and taped them to the hull which did a decent job holding the tension in this case. It was difficult to wet out the layers of glass, but I expected this. I used roving on the furthest inside and 2 layers of mat next to the hull. I did it in the sun, temps are getting low, and it started hardening up on me.

The keel was a bit different. I just put 2 strings across the opening and had a piece of cardboard with butterfly wings I folded over. I did pre-coat the resin on the inside of the hull. I got some resin on the foam block inside and it melted some. More room to do work. Wet out the glass was hard to get into the hole. It was not pretty. The sun had gone behind the house and the temps were lower, I had a lot more time to work. I also now know about the color change as the resin cures. This one will need a bit of sanding to get it down low enough.

Temps are a bit low for me to do a lot work here in NJ. This is a side project with little rush. Both backers I am please with in that they are hard and seem well installed. The chine has a couple of bubbles in it. I expected that and I am not worried.

After what ever sanding needs to be done to level high spots I will move on to layering in glass. Start with mat then roving and continue until finish with 2 layers of mat. That should be pretty simple. I also need to thicken some resin and fill in some voids here and there. I have 2 more spots with some damage that just need a few layers of glass and then gel coat. Then on to the top side where I need to cut a larger hole in the deck (it has a port put in but it is small) to fix the cleat.
 

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For your very first effort, that's not bad... are the air bubbles close enough to the surface where you can sand 'em open, then fill 'em? Another idea is to go ahead and install an inspection port topside, that way you can beef up the glasswork from the inside... but I seem to recall you did NOT want to do this? I don't know why, there's nothing wrong with having an inspection port, and you don't have to put it on deck, you can use a cockpit bulkhead. :confused:

Anyway, that's not bad work, and don't sweat the apparent ugliness as you proceed with repairs, everything will eventually be covered, and if you do THAT correctly then nobody will ever know, LOL. That's the ultimate goal with repairs like these: to make them solid and cover up all signs that any repair work was actually done. Easier to do with paint than gelcoat, but that's a choice you'll have to make. :rolleyes:

Okay, I just read your post again, and there IS an inspection port topside? Sure, make it larger, that's easy enough to do. You said there's foam behind the damaged area? Any way to get past or around it from the inside of the hull? If not, don't worry, I think you'll be alright if you keep doing what you're doing here, you're certainly off to a good start. Just watch those air bubbles, you don't want any of those if you can help it, as they lead to weakness. :eek:

Otherwise, I say, "Good job, especially for your first time doing glasswork!" And I say that as someone who has done more glasswork than I care to remember. We'll see what others here say... MixMkr knows about glasswork, maybe he'll chime in on this particular job. Oh, yeah, lose the strings as soon as you can, if you can't punch 'em into the hull (stout needle or awl) then get as much of 'em out as possible, then fill the holes and start building on top of them, aye? ;)

I'M OFF TO GET ANOTHER CUPPA TEA, I USE THESE HERBAL TEA BAGS TWICE BECAUSE I'M A CHEAP B@STARD, LOL... GOOD JOB!!! :cool:
 
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I wanted to do the repair from the frontside. Later I have a smaller hole in my son's Sunfish that will do with a blind patch. It is a small area at the bow and I really do not want to put a port in the deck as it will not look as nice. So this was just some practice for a later repair.

There is a port on the deck currently, but not in the right place. I will have to have a hole in the deck eventually to do a repair to the cleat. The cleat block was broken away from the deck so the cleat is loose hanging down into the deck. The deck port is also a smaller sized one and would have to be made larger to get an arm in for a repair. I believe the foam block would prevent access from the hole, so I am expecting to make a second deck hole. Have to finish the bottom side first. That will go slow cause the temps are too low right now.
 
Roger that, I just happened to be checking the site when I saw your reply, LOL. You already have the curve laid in for a start, so that's a good beginning... and you should be able to finish the repair without installing another port, you'll just have the strings and twigs to deal with, but that's no major issue. Cut 'em as short as you can to the repair, then see if you can't push 'em into the hull... or leave 'em attached, though you'll wanna scrape out as much string as possible before filling the holes. As long as you're building more layers atop what you have there, you'll be fine. :rolleyes:

I still think it's a good job of work so far, and I know how easy it is to get flustered when you're wetting up glass and it's not cooperating, especially in compound curves. Sometimes ya just gotta do the best you can, let the work cure, and go from there... that's one good thing about working with glass, you can always add more or sand & grind it away. Do you have a Dremel Tool or a file? Those could get you into those air bubbles... a drill could too, just far enough so you could fill the holes, some folks wouldn't bother, but I like my repairs solid all the way through. Just my $.02, FWIW. ;)

WELL, I THINK IT'S ABOUT TIME FOR A BOOK OR A MOVIE... WESTERN IN EITHER CASE, LOL. I'M LIVIN' THE WESTERN DREAM... :cool:
 
Your repair is a variation of what I'd suggested in a previous discussion (here).

To tackle the compound curves in the damaged area would be facilitated by forming the patch over the chine. (Making an angle-patch).
 
I like what has been done... and it'll be a tad thicker (i.e. stronger) that way, even if the manila folder and twigs and whatnot remain entombed, LOL. :confused:

OP, I remember using fishing line instead of string to hold one cardboard 'backing plate' in place... toothpicks instead of twigs, as the line and toothpicks were the only things readily available at the time when I scrounged for materials. I didn't wanna use nails or brads because they'd eventually rust, and the parachute cord I had seemed like overkill. The line worked alright, it was some stout test that had been kicking around the tool cabinet for months, if not years... ;)

Oh, yeah, I also wrapped the cardboard in plastic (Saran) so it wouldn't get saturated with resin, become soggy and lose its shape... just another minor detail mined from memory. It has been a while since I did any glasswork with 'backing plates' (as I always called 'em, simple 'backing' would work but the 'plates' sounded nautical, LOL). :rolleyes:

Just finished reading BLACK POWDER, WHITE SMOKE by Loren D. Estleman, that was an entertaining book. I chose it from the library stack because I recently read another of his books, SUDDEN COUNTRY, and I enjoyed that one too. Ever since I arrived in Arizona roughly four years ago, I've read Westerns written by many different authors, and some of them are quite good. :cool:
 
In my case I wanted the cardboard to be wet out.

I figured it would conform to the shape better, but give enough form to get the glass to touch the edges.
 
In my case I wanted the cardboard to be wet out. I figured it would conform to the shape better, but give enough form to get the glass to touch the edges.

Well, I suppose the thickness of the cardboard would also be a factor... I may be remembering some thin cardboard that got soggy, LOL. :confused:
 
That's what I said!!! LOL... hey, SC, I hope your post-hurricane cleanup efforts are going well!!! That looked like a pretty good hit on the property, but at least you and yours are there to handle your business!!! I have faith in y'all, you're good people and you'll get through all that, I just know it... ;)
 
I put a few more layers of glass on. I have more to learn as I messed up some. Structurally I believe I am good, I just am curious if I can get the gel coat on and level.
Still need to put down a layer or two of mat here. I have the keel needing a few layers of mat and some gel coat digs that need some mat to build up thickness.
Then shape and gel coat.

I have to work on it mid afternoon when the sun is up otherwise it gets too cold. Needed the heat gun to get a cure.
 

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Recently, a member described methods to get an even coating in gelcoat.

My one take-away was to use wax paper to smooth an even surface. (Manipulate it with your hands and fingers).
 
Considering that this is your first repair ever, I think you're doing a damned good job... and you'll learn from those mistakes, same as in other walks of life. :confused:

Just finished WHITE DESERT by Loren D. Estleman, that guy can turn out some pretty good stories. Laugh-out-loud hilarious at times too, and I reckon a little humor never hurt in this mean ol' world, LOL. ;)
 
No mention of epoxy in your repair--a good thing! This just appeared at the Mariner-class website:

"If you intend to gelcoat this, you may not want to fill the gaps with epoxy. Gelcoat is a polyester resin and does not bond well to epoxy. You would be better using a polyester resin to fill in the cracks so you don't run into problems with the gelcoat process".
 
How cold is it getting? Fast hardeners work down to around 40F

Getting down around 60 to upper fifties.

Part of the issue is the time I am working on it. After work at 4. The sun is out and warm then it tapers off really really fast. So it sets fast with the high end of drops, but the second batch did not cure an hour + later till I got the heat gun out. I guess if it just worked later and gave it a drop or two extra in a cooler environment.

The next step is just laying down some mat till level on the repairs and some mat to level some bad areas of gel coat where the upper level of glass was bad too. I have like 5 small areas that need some mat, some sanding then gel coat.

It rained today so I felt it best not to play. Tomorrow should be better.
 
Skip the glasswork in wet weather, same way you'd skip painting unless you were in some weatherproof shop with climate control. :rolleyes:
 

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