I'm sure all you Waveblasters have stress cracks on the rear hull (transom) from BIG wave jumping sessions...

I'm at the point where one more jump is going to sink my boat! Lake Ontario has taken its toll!
The fiberglass isn't cracked through yet, but the gel coat has "crosshatched" stress cracks and is beginning to chip off, especially at the upper corners of the pump cavity.

The wall thickness is very thin... when I installed Riva Thru-the-Hull exhausts on both my Blasters years ago, I found that one boat was only 1/8" thick while my other one was 3/16" thick, both 1996 models. Poor Quality Control...I guess that is the downfall of hand-laid fiberglass.

So, what have you done to fix it? I plan to remove the rear mat and cut an access panel out of the floor. From there, I will remove the foam and beef-up the wall thickness along with fiberglassing vertical strenghtneing ribs approxiamtely every 2". Then I'll glass-in a mounting flange for the removed floor piece and screw the floor panel down for future repair access. I'll finish with a nice new set of Hydro-Turf Mats and regelcoat the outside. Any thoughts, advice, etc?

Thanks!
Greg

don't waste your time on the gel code will break againg mi frind rian broke these 3 times last sumer i will talk to him to post same info later

One of the problems that leads to the stress cracks is the lack of support in the transom area of the Blaster's hull. I know several owners that have removed their battery tray, built up a dam and then injected expanding foam (Great Stuff is one such product available at Home Depot) into the rear area of the hull on both sides. This helps absorb the compression the hull experiences upon landing on the tail when wave jumping. The foam fills the void and prevents the hull from flexing!

The only down side is if you need to do any work in the back of the craft later you will need to dig out the foam. The upside is you won't need to worry as much about the stress fractures.

My 96 Blaster had the same stress cracks in the are you described, however not to the point of the jel coat chipping off.

I was using an aftermarket ride plate (much longer than stock) on mine and I'm wondering if that might at contributed to the stess cracks.
When re-entering the water the ride plate puts more stress on the rear of the hull right above the rear ride plate bolts causing more stress than than the hull was designed for???

Are you running an aftermarket ride plate?

I agree with Riva on their Reply... the Hull flexes too much. The foam is a great idea.

My plan was to build up the rear wall thickness from the back by laminating in a polyurethane foam core (The Great Stuff Foam is a polyurethane foam as well) with another 3/16 hand-laid wall on top and around the corners to the sides. Then, I was going to add the vertical strnegthening ribs. These ribs would stiffen the wall and perform like the ribs you see sheet metal workers add to duct work, etc.

I do run an aftermarket rideplate and agree that it can add some stress when landing at an angle, but I often land completely vertical which subjects the transon wall to enormous compression stress. Basically, it's like a trying to shove a brick wall into the water at a high rate of spedd... NOT GOOD!


Despite all this... I LOVE MY BLASTERS!