Fibreglass repair?

[sleddriver]

2' is a long crack. That's a bad place too. How deep? How wide? Which side of engine rotation is it on? Engine torque comes to mind though that's just a WA guess. I'm curious if there are more cracks hidden by the engine? Also curious if 'this old boat' was rode fast & hard @ WFO in the rough. Some guys go for that and beat the hull to death.

If it was in the muck-o-the-bilge, you'll need to thoroughly debris & degrease & possibly de-motor.

What are the odds of getting your money back?

 

[wrcsixeight]

Polyester resin does not have as high a bond strength as Epoxy, and is not as flexible, but is significantly cheaper and easier to work woth, other than the excessive eye watering lingering fumes.

Proper surface prep is extremely important, and contaminated bilge water feeding a long crack that has been there a while with lots of flexing going on is very much undesirable.

Before any sanding, scrubbing with acetone with many a dollar store scrubbie sponge in one hand and a clean rag in the other to immediately absorb that which as loosened in the other, is a good starting point. Get the entire area as spotless as possible in this manner. Do not allow acetone to puddle, as it will begin to soften the resin. Pick away any loose fiberglass in the immediate area of the crack and let it breathe out and dry. Do not try and speed up this drying by the application of too much heat too fast. Keep it under 120f.

Do Not do ANY sanding, until the surface is completely free of contaminents, as sanding would merely force them into the sanding scratches impeding subsequent secondary bonding.

Once the wood near the crack is as dry as it is going to get, iuing some sort of filler like microballoons or cab o sil or fumed silica, to fill the void is required, and then rebuilding the skin over the crack should be done with feathering the strength and thickness of the repair/reinforcement in mind, as any hugely strong spot, induces a weak spot right next to it.

Another good read is the Epoxy book By System 3 resins.

https://www.systemthree.com/pages/literature

Proper mixing of epoxy cannot be stressed enough, both in ratio and thoroughness within the mixing cup. Mixing by volume can lead to errors and epoxy not upto its full strength characteristics, and removing this epoxy is an absolute nightmare.

Make sure the mixing stick can get into the corners of the cup, scrape all 5 sides of the mixing stick on the side of the cup and mix these drips back into the rest of it thoroughly, do not allow any to drip down the outside of the cup, and mix it twice as long as you think is required. Strong light will often reveal swirlies in the mixing cup that would otherwise go unnoticed and lead to an improper cure if applied. Always mix epoxy resin and hardener thoroughly and completely. there is little room for error, and fixing errors it 3x the amount of work, minimum.

Epoxy is not cheap but it is superior in every way, but for resistance to UV light and excessive heat. It is not as forgiving as polyester resins to work with, and this area is why it is often spoken poorly about, by those used to working with polyester resins.

Most epoxy has little VOCs and only a slight smell, but I can smell polyester resins a mile off.

Cured Epoxy dust is inert, but when not fully cured it is still toxic, and some can react badly to it, and some will develop a sensitivity to it and cannot be anywhere near it once this sensitivity is developed. So take precautions, and do not clean any epoxy that gets on one's skin with Acetone. Distilled white vinegar can be used to clean application tools, and skin of epoxy where as with polyester resin one has to use acetone, and human skin presents no barrier to acetone.

 

[OVERKILL]

Originally Posted By: sleddriver
2' is a long crack. That's a bad place too. How deep? How wide? Which side of engine rotation is it on? Engine torque comes to mind though that's just a WA guess. I'm curious if there are more cracks hidden by the engine? Also curious if 'this old boat' was rode fast & hard @ WFO in the rough. Some guys go for that and beat the hull to death.

If it was in the muck-o-the-bilge, you'll need to thoroughly debris & degrease & possibly de-motor.

What are the odds of getting your money back?


We took it to a hull repair guy yesterday for evaluation. He figures somebody belly-flopped it off a huge wake and that this is relatively common. Despite the length, it isn't that deep and there's a sister crack just out from the stringer on the driver side, just not as long. His advice was quite similar to BrocLuno's, which is to keep an eye on it and to get it properly repaired, which will involve pulling the engine.

He said for now, put it in the water, use it, but keep an eye on it. Also, to avoid hole-shot acceleration, which means no skiing. Tubing is fine, as is wakeboarding. He said we'll probably be fine to use it for the season if we do that, and then to pull the engine and bring it back to him in the fall and he'll repair it as a few have mentioned, both sides. Cost is gonna be around $1,200 to $1,500, so considering what we got the boat for, and the hours on it, we are still quite ahead of the game.

We purchased the boat for the cost of storage, fully knowing it was being sold "as is" and that there was a bit of a project nature to it. Both the mechanical and electrical for me are well within my comfort zone, but the vast majority of boats I worked on growing up were wooden, so I have basically zero experiencing fixing fibreglass, hence the thread.

 

[OVERKILL]

Originally Posted By: maxdustington
Would you post some pics of the boat and motor please? Pictures of the cracks are optional.


Sure:

 

[wrcsixeight]

I once worked in a boatyard, laying fiberglass into a large mold and then glassing the stringers in place. The original owner had died, and the son was now boss as well as Mr arrogant cost cutter.

I was in charge of cutting the stringers to later glass into this one hull, and the 2x6's I was told to use, were all wavy and filled with knots, right where the motor was to reside upon them. I pointed this out to the boss, that no way if this were my boat, would this wavy grain with multiple knots be acceptable for this duty, and he just said the strength of the fiberglass would nullify that of the wood below it, and I was forced to proceed doing something very much subpar.

They were just 16' 2x6 from home depot, still wet, and looked like they just pulled off the ones on top that real carpenters has discarded as subpar.

I'd laid some extra fiberglass on a wet offcut and set it off to the side, and came back a couple days later and pulled on the fiberglass. It popped right off the wet lumber as if it were a waxed mold.

I wonder how much money he saved buying and using that subpar lumber for such a duty.

They went under not too long after I quit in disgust.