Trailer Damage

[Steve]

Hi Geoff,
that's a bit of a bummer, but mine was a simple fix and I'm sure yours will be too.
I just used a general purpose polyester resin, catalyst at 1% and 225g csm. Finished with a polyester resin filler and top coat which is your jell coat with the styrene wax added so it will air cure. My son Kev, put me onto "Brumby strip it disks" available at Bunning's for about $15 a pop. They fit on an angle grinder and they just love to eat fiberglass. If you remove the gel coat from over the suspect area first It will give you an idea of the damage, just look for the soft white bruising effect of delaminating. Once I had established the damaged area I started dishing it or scarping it out till the damaged piece broke out. I continued to dish it so I had a tapering area out from the edge of the hole I had made, roughly a distance of 12- 15 times the thickness of the hull. If you make a template from paper, of the total area you need to repair, you then use that template to trace around onto your csm. Cut out that piece of csm. You will need to trim some off the edge of the template e.g. 1/2"all the way around it and cut another piece off csm the new size, Keep repeating this process until you have enough pieces to make the thickness of hull and they all should be the same shape but from big to small, when you stack all the pieces together they should resemble the piece you have ground away.
You might want to use epoxy resin, it adheres to the old glass and resin better, I just prefer polyester for this type of repair. If you use epoxy be mindful of the heat you can create in one spot.
http://www.youtube.com/watch?v=SsoKAHU5xUw
Have a look at this It explains it pretty well but the repair is done from the inside with gelcoat going on first, there are other clips on youtube that work from the outside.
Steve

[geoffr]

That's great advice Steve; thankyou so much!

In a macabre way, I'm actually looking forward to the challenge of fixing this myself, given that repairing a hole in a fiberglass boat is probably something all boat owners should know about and deal with at some stage in their ownership.

I was mostly hesitant about how to begin, but your explanation makes great sense. It will be a delight actually to rid my boat of what has clearly become a true weak spot: a spongy area that could worsen at any moment with fixing, and which lies below the water line.

I'll post some pics as I proceed, which may be of help to others.

Cheers,

[geoffr]

Hi all:

As promised, here are some pics of my damaged hull -- similar to Steve's.

They look particularly dramatic taken with a flash, as it shows EVERY imperfection in the hull.

I'll take further pics as I repair this for others to reference, if needs be. The video link Steve provided is very helpful too.

Cheers,

[Steve]

Geoff,
yep! looks very familiar, just remember that what ever you do now to fix it will drastically improve the situation, Scarp that new glass in and it has to be better than a delaminated hull puncture wound. If your not happy with the repair, do it again, your not going to do any more harm. Don't be afraid to waste a little resin, that is my biggest hurdle, I hate to waste stuff ,e.g. it is cheaper to throw away brushes than to waste a litre of acetone cleaning them, I still struggle with that though. I now always mix more resin that I require because there is nothing more frustrating than running out,,,, panic sets in ,,,,, did I mix the extra batch enough, I hope it cures, is there now too much heat,,, and you know what, the resin that I saved will probably sit on the shelf and I will never use it any way because next time I need some I will panic it has expired and gone off. To sum it up, the materials to fix my hull damage cost me about the same as a carton of beer and the time I spent fixing it was less than the time It would take me to drink that beer,
Steve

[geoffr]

Hi again all:

I've spent a few hours this weekend (in between showers) working on my damaged hull.

Using my grinder and the disc Steve recommended (which worked a treat on fibreglass), I soon had the gelcoat off. As you will see in the photos, it had well and truly separated from the glass hull structure beneath, allowing me to almost peel it away like a giant scab (about 1mm thick).

Once this was gone, I was able to better inspect the damaged area. Fortunately, the inner glass hull was not fractured or cracked -- just spongy, and indented by about 10 mm from the ideal shape of the hull in the surrounding areas.

Over time, I think the roller has compressed the expanded foam material on the inside of the damaged area, to such an extent that the foam can't push the hull back out into shape when the roller pressure is not there. As well, the roller had caused the gelcoat to separate and start to buckle.

I ground the inner layers a little, just to roughen them up enough to take some new glass and resin.

I then followed Steve's advice and used a paper template to cut some progressively smaller glass matt pieces, ready to lay into the indentation, and pack it back out to the ideal shape.

I mixed up just enough resin to do half of these at a time, allowing about an hour in between for drying.

I'm very pleased with the resulting shape: the hull in the previously damaged area is now rock hard, with no sponginess whatsoever.

It's now been sanded back (using 80 grit wood discs on my small orbital disc sander), and is ready for the final exterior coat.

A local fibreglass repairer advised me not to use gel coat, as it would not bond and dry well enough to produce the finish I needed. Instead, he recommended two-pack polyurethane boat hull paint, which I bought at a local auto paint shop in Geelong (at half price, as it was a clearance item). It's still not cheap, but if it does the job then it's money well spent.

The painting will have to wait for a dry weekend; I'll keep you all posted.

Cheers,

[Steve]

Looks like you got it easy Geoff, I find I am continually thinking should I,, or shouldn't I,, on the other side of the hull, Let us know how the painting goes, I'm wanting to respray my hull with flowcoat, but maybe I should use paint?
Steve

[Brendan]

A bit of a late reply but i would add proper side bunks and do away with the wobble rollers. That is what i am doing. Even though the side rollers only hold the boat up and not carry any weight the constant rockling when towing will wear the hull where they touch. Just not enough surface area.

[geoffr]

Hi again folks:

A belated update on the hull repair ...

I've now given the repaired area two coats of white flow-coat, sanding back in between.

Applied with a brush, it's not the smoothest finish in the world, but it is a vast improvement on the damage that was there previously - so it will do for the time being.

Once the hull is back in the water for a few days over summer, and the marine growth starts to yellow the painted area, I will defy anyone to tell much the difference.

The important thing is that this section of previously spongey hull is now rock solid again, so the cosmetics don't worry me so much.

I'll post some pics soon.

I've also thought about replacing the wobble rollers and will do so at a future stage, but I'd rather put any 'spare' funds towards a new mainsail.

Cheers, Geoff

[Andrew]

Hi All,

I'm going through a trailer maintenance phase. On test sail #1 the boat was stuck on the trailer awhile, after checking the see if the centerboard was stopping it, we went in deeper, pushed harder and it moved off. The trailer is a break-back.

I bought 2 replacement rollers for the back end of the trailer. I wanted a black one to match the others but the chandler advised me that fiberglass boats need a harder compound roller, so i got red and blue ones. There are black rollers on there already but they are softer rubber - the 2nd rear ones axle has bent and it barely turns now - possibly one reason why the boat got held up on launching?

Second rear roller, bent

Rear rollers and hull suports

The rear roller cluster probably needs to be rebuilt. The side guide rollers are seized, tho they do work as slider guides. The rear roller has no height adjustment, i plan to cut it off and replace with an adjustable one and set it lower than the present one.

The hull supports are wooden blocks with carpet, they have some hinged movement to align with hull. Their frames are welded. and these seem to work ok, distributing load evenly on the hull, providing the keel rollers are height adjusted correctly (i suspect they're not, too much weight on the hull pads, so hard to launch?)

We had no trouble getting the boat back on the trailer rollerwise. but the old winch is currently a 2 person operated affair, one must hold the release lever up while another pulls the cable down to the boat bow eye...

[camanche73]

I replaced the keel rollers with a full length timber beam as well as having bunks to support the hull. Find it displaces weight better and holds the boat more stable. Downside is it does not come off the trailer as easily. Although now I quite like this feature- it's either deep enough to float the boat, or it's not.