Reparing the main hatch.

Mar 20, 2015
3,094
C&C 30 Mk1 Winnipeg
Good Morning All,

Long time no "see". or maybe "sea" ? :)

My main hatch is cracked on the bottom where the bottom fibreglass section meets the side.
The crack then progressed up the front port edge and 1 inch into the top section.
Water has damaged the core.

I'm thinking that I should cut the glass on the underside, along the edge, rebuild the core, fix the top crack, and bond the bottom back on.

My concern is keeping the hatch in the correct shape/curve. while I'm doing this.
Any suggestions on how to build a jig so the hatch retains it's correct shape while I'm repairing it ?

Cheers,
Roy
 
Sep 8, 2014
2,551
Catalina 22 Swing Keel San Diego
Roy... I get the general idea but not completely sure. Throw some pictures up if you get a chance.
I'm wondering how extensive the damage to the core is. Since we are talking about the hatch cover I would guess that weight isn't the biggest concern, so maybe just grinding out the crack a little wide, dig out damaged core, and fill with thickened epoxy. Then repair/strengthen the glass with tape on the inside where it matters less cosmetically. That way you don't have to cut out the entire interior panel of glass. I have a feeling, even if you did, the hatch cover would still retain its shape. Its the sides that would remain un-cut and do the most work in structural integrity.
Worst case (if it were to get flimsy), before you cut it - put it into a tray of sand and push it down into the sand until makes a mold of the curve all the way up the side edges. You can use a water based glue, Elmers school glue should work... water it down and add it to the sand until damp, before you press the hatch into the sand; when it dries it will hold the shape. Just make sure to wax the hatch top, LOL...
 
Mar 20, 2015
3,094
C&C 30 Mk1 Winnipeg
Photos coming... Just starting to think about this project so haven't got the hatch handy.
(I've got to fix up a few things on the car in prep for selling it, first.)
 
Nov 19, 2008
2,129
Catalina C-22 MK-II Parrish, FL
Leeward, I had the same issue on my original C-22. Now here's what I did, probably lots of other ways. I simply removed the hatch and turned it upside-down. Here's the BIG job.... I ground and sanded all the paint off, so there is bare fiberglass on the entire side. I applied several layers of fiberglass cloth, enough to cover the entire surface. I built up the edges where it wears down from sliding back and forth with some fiberglass tape. The ridges on the top side are a foam cored. I also had some access holes and just let resin seep in to fill them a bit. Naturally the resin I used was WEST epoxy,(it's all I ever use). You won't believe how much stronger just a couple layers of epoxy saturated cloth will make the sliding hatch! After everything cured, and I sanded the edges, I prepped the inside and gave it a couple coats of white polyurethane topside enamel. Looked GREAT, and my big butt could stand on it without it bowing.

Don
 
Mar 20, 2015
3,094
C&C 30 Mk1 Winnipeg
Thanks Don, that sounds like just the ticket.

I had also wondered about simply injecting epoxy into the core with the cracked section clamped in position to do the basic repair.
Once it cured, reinforce the bottom. Especially the lip/rail/edges.

I've also wondered about some way to make the hatch easier to slide, while reducing wear on the parts.
I've read a couple threads where people attempted to do that.
Polished stainless steel extrusion or something on the bottom of the slot in the teak.... hmm.
This is one case where the replacement HDPE rails make more functional sense than the original teak.

Between the friction, and the relatively thin edges on the hatch, I'm surprised that every C22 doesn't have cracked hatches.

I'll report back, with photos, once I get the hatch and rails from storage.

Too many damn projects to get done, and it's still winter. hehe
 
Sep 8, 2014
2,551
Catalina 22 Swing Keel San Diego
Wow.... I feel silly. I thought Roy was talking about the FWD hatch, LOL. MUCH smaller than the main sliding hatch! If you used my 'sandbox' method to make a mold, that would be one BIG sandbox!
 
Mar 20, 2015
3,094
C&C 30 Mk1 Winnipeg
Thank Gene, that's a good thread. My forum search missed that for some reason. I suspect I mistakenly restricted it to the C22 forum only.
For those reading this thread later, it mentions Stingy's blog, which also covers his hatch repair. (I read that last summer)

Luke, hehe no worries. Your repair info would apply to the main hatch, even if the sand mold idea didn't. But in your defence without photos it's hard to make any suggestions. :)
 
Mar 20, 2015
3,094
C&C 30 Mk1 Winnipeg
Had some spare moments tonight to take a look at the hatch.

It's worse than I expected.

Besides a crack in one corner, there are cracks on all four sides of the hatch, along the edge between the top and bottom sections of fibreglass, and the front top edge is broken.

And now the photos....

tmp_21577-IMAG03391418254410.jpg

Rear starboard corner.

tmp_21577-IMAG0340-205199234.jpg

Starboard side


tmp_21577-IMAG0345_1566245064.jpg

Forward starboard corner

tmp_21577-IMAG0342-1590085276.jpg

Forward port side

tmp_21577-IMAG0343_1-1372486881.jpg

Forward edge

tmp_21577-IMAG0346_1856031377.jpg

Forward top edge
 
Last edited:
Mar 20, 2015
3,094
C&C 30 Mk1 Winnipeg
Looks like the plan is to

  • remove the whole bottom fibreglass skin
  • repair the top corner and forward edge
  • Repair core
  • Bond bottom skin back on
  • Reinforce the rails
Not 100% sure how I'll get the bottom skin off.
It almost looks like I could slowly split the edge along it's existing split areas, simply by slowly prying it apart, but I'm worried that may cause more damage due to a lack of control.
Another option is to use a dremel style saw to cut the edge.

It's late so I'll figure that out another day.
 
Last edited:
Mar 20, 2015
3,094
C&C 30 Mk1 Winnipeg
Well, to answer my above question, I did both.
I used a small chisel, along with plastic wedges and a rubber mallet to gently work the bottom skin away from the core.

I started where the split/delamination was already serious, then slowly worked my way across the skin and along the edges. I used the chisel to open existing smaller cracks enough to get the plastic wedges in. I then gently tapped the wedges to lift the skin from the core.
The skin cracked along the edge, in line with the existing cracks

I used a long pry bar once the wedges weren't long enough.

Along the rear edge, where hatch pull handle is, I used a rotary blade in a dremel style tool, to cut along the bottom, about 1/2" from the inner corner, just deep enough to cut through the fibreglass skin. (Mine is a Harbour Fright unit, made in China and the label says "rotay tool". Give me an "r" Alex.)

Eventually the skin was loose, and I discovered that a repair had been previously attempted.
In addition I found some rotten plywood core, and a layer of blue colored substance.

Does anyone have an idea what the blue stuff is and why they used it ?
It looks like blue sponge toffee.

tmp_15749-IMAG0347_1~01-244762612.jpg

Bottom skin removed from hatch.
Water damaged core section in corner.

tmp_15749-IMAG0348~012071690773.jpg

Close up of water damaged core area, plywood core, and blue sponge toffee like layer.
 
Last edited:
Mar 20, 2015
3,094
C&C 30 Mk1 Winnipeg
That would make sense. They likely used a mould for the top of the hatch, and hand formed the bottom skin, So they would need to fair the surface before applying the glass.

Can you tell I've never done this ?

Kinda reminds me of a blue towel.
 
Sep 8, 2014
2,551
Catalina 22 Swing Keel San Diego
I second that on the blue stuff, but rather than call it fairing compound I'd call it thickened adhesive, polyester based. The reason I say not fairing compound is because it isn't very easy to sand as fairing compound should be. This hardened blue goop is what was holding by rotted wood battery tray down. Once I chiseled away the rotten plywood (pretty easy) it was a bear to sand all that down even with 60 grit. Some of it I even hit with the 40 grit ceramic belt on the 8 inch belt sander and it didn't go very quick.
 
Jul 13, 2015
893
Catalina 22 #2552 2252 Kennewick, WA
Interesting-- I had a similar middle layer of epoxy based something in the cockpit floor, but nothing quite that blue. Definitely the "glue" for that particular layup.
 
Mar 20, 2015
3,094
C&C 30 Mk1 Winnipeg
Under the plywood, there appears to only be resin and glass for the top layer of the hatch.

The blue stuff is, in most areas, well attached to the plywood. I'm thinking to remove the bad plywood, and any loose blue stuff, in addition to whatever someone previously used in an attempt to fix the hatch. (I thought it was yellowed resin but it's more the consistency of old sealant. Soft and flexible)

tmp_21412-IMAG0350~01-352189707.jpg

Bottom skin with old material from PO's bad repair

I have now used a chisel along the edge of the blue stuff so that the skin can go back on without the blue stuff on both halves interfering where they meet.

Do you think I could put a bunch of epoxy down, that could fill any gaps, and simply clamp it together... Squeezing the excess out ? (after replacing the rotten core areas of course)
 
Mar 20, 2015
3,094
C&C 30 Mk1 Winnipeg
Well... the skin us back on.
Fingers crossed.

As planned, I removed all the loose blue stuff, and whatever a PO used for the failed repair.
I had some llywood left over from modifying the galley, which was the same thickness as the original core, so I bonded it in place while fixing the crack in the corner.

I had been worried about getting the original curve back into the top skin (the crack allowed the left side to sink lower than original).
I needn't have worried. The curve is fairly minor at the extreme sides. In fact it's almost flat, so I simply used some wood to clamp everything together, and the curve turned out well.

After leaving it for a day,to cure, I removed the clamps and moved on to epoxying the bottom skin on.

All I can say is... "Wow ! Does the amount of epoxy sure make a difference in curing time"
I used 32 "pumps" of west system epoxy in total, with 406 adhesive filler added into the mix.
I mixed it in 4 batches, and it still "set up" faster than expected.

It worked out, but I was forced to rush, and forgot to mix some pure epoxy to "wet" the skin down before I clamped it in place. (I wanted to "wet" both halves down but only did the one half)

I got the skin lined up and clamped + weighted it down to force the excess epoxy out of the edges.

My guess, at home much epoxy was needed, was a bit too close for comfort. I had used enough to "just" have it squeeze out the edges.

I used a combination of various clamps and weights to hold the skin down.
I used wood spacers on either side, to ensure the weight didn't force hatch flatter while it was curing.

tmp_3273-IMAG0357~01408956207.jpg



If all goes well I'll be building up the rail edges tomorrow.
 
Last edited:
Mar 20, 2015
3,094
C&C 30 Mk1 Winnipeg
Morning all.
Hatch is structurally sound now.
After the 2 halves were epoxied together, I took a screwdriver and tapped around the bottom skin looking for any hollow sounding areas, to find any places were there wasn't enough epoxy.

Unfortunately, I found 2 areas that needed additional epoxy.
In both areas, I drilled small holes (2 in one area, and 1 in the tiny area), and injected epoxy with a syringe, until the void was full. It this case it didn't need much.
Since the original epoxy was cured, I wouldn't get a chemical bond, and obviously there was no way to abrade the surface inside the void, to ensure a strong mechanical bond. But... the original blue fairing/filler compound has a bunch of bubble holes, and the skin was fairly rough so I think where the voids were should be bonded well.
No worries anyhow, since the rest of the area bonded correctly the first time.
It sure seems solid now !
The sound, when tapping on all areas of the hatch, is much better than it was before the repair.

I figure I'll use @Gene Neill and @T_Cat 's method and try some hatch dancing later. Hehe.

Once the halves were done, I used epoxy and glass tape to build up the rail edges, while ensuring it would still fit in the slot in the teak tracks.

I then used epoxy + sanding filler to fair any of the areas that weren't smooth.
This included filling and fairing the small crack, created by the dremel saw, at the rear/bottom of the hatch.

tmp_13516-IMG_20160717_1105061163948727.jpg

Ready for gelcoat

Now it's time to match and spray some gelcoat.
I was going to spray the whole hatch, but I'm worried that the gelcoat will still be thick enough, after thinning, to fill in too much of the non-skid. Instead, I think I will mask off the non-skid and spray the rest.

I'm going to try manually matching the colour. Since it's a whole hull component, if the colour is off a bit, it won't be noticable. I'd rather use this as an opportunity to learn how to match gelcoat, than pay a lot more $ buying custom tinted gelcoat from some place like spectrum.

That will need to wait a bit. Rain and thunder has started.
 
Last edited:
Sep 30, 2013
3,538
1988 Catalina 22 North Florida
Bravo, nice work!!

I didn't tint the gelcoat on mine at all, just shot it stark white . No one would ever notice in a billion years. But if you do tint it, all you need is a tiny tiny tiny speck of brown pigment. TINY.
 
Mar 20, 2015
3,094
C&C 30 Mk1 Winnipeg
...if you do tint it, all you need is a tiny tiny tiny speck of brown pigment. TINY.
I figure I may as well give gelcoat color matching a shot, even if it's only as a learning experience.
The gelcoat I found locally is brushing viscosity, and will likely need to be thinned for spraying.
I was going to use laminating/non-waxed gelcoat for the experience of using PVA, but all they had in stock was waxed.

What I found interesting is, the epoxy+filler combo came out very close to the gelcoat color on the bottom of the hatch.
Unless my eyes were deceiving me, it appears that the gelcoat on the top of the hatch is different from the interior (more cream coloured), even after sanding the oxidization away on both sides in a test area.
I'll confirm that tomorrow once the rain stops, and I can compare it to the hull.


I found a great youtube channel run by a guy by the name of Andy Miller, who is a professional marine repair guy.
He has some great, detailed videos about matching gelcoat, repairing holes, paint, etc. etc.
I plan on using his technique to make a mold from the existing non-skid.
http://boatworkstoday.com/video-page
 
Last edited: