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Backed into a rock, found cracks near impeller. Is this a major issue?

sudoMakeMeASandwich

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So last night, we had a new driver driving the boat. While docking they got spooked and they backed up (with moderate speed) into some riprap (rocks):banghead:. I didn't see any obvious damage last night, and the bilge wasn't filling with water (any more than usual) so I decided to leave it in and take it out this morning.

This morning I took it out and noticed that there didn't seem to be any damage, but there are some cracks along the left side, where the impeller connects to the boat. I have no idea if that was caused by the incident last night or have been there longer, but is this something I need to worry about right now, or can it wait until the end of the season to get fixed?

Also, does anyone know of a reputable fiberglass shop in east TN or North GA?
 

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cgcaraway

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Viking Boat and Fiberglass.
Amazing company and people. They are located near Smyrna, GA. Hope this helps.
 

Scottintexas

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I might pull the cleanout tray and look at it from the inside,

does it feel stable if you push on it ?


.
 

Matts18

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I used the guys at Smokey Mountain Marine and Fiberglass in Maynardville TN. They do great work but are usually pretty backed up. I would want that damage fixed pretty soon as that area is likely under a decent amount of stress.
 

jmargo

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I have similar spider cracks around the bolts that mount the drive to the boat. Figured it was just from all the vibration back there.
 

sudoMakeMeASandwich

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I might pull the cleanout tray and look at it from the inside,

does it feel stable if you push on it ?


.
I didn't check stability. I'll check that and pull the tray this afternoon and see what is going on inside.

I have similar spider cracks around the bolts that mount the drive to the boat. Figured it was just from all the vibration back there.
I am not as worried about the crazing around the bolts (although it doesn't make me happy), but what worries me more is the "smushed" fiberglass in the bottom corner. As @Matts18 pointed out, it's a high-stress area of the boat and I want to make sure that no major problems are going to come out of this. I'll get everything fixed, its just a matter of when, we have people down for July, so if it can stay like it is for a bit, I'd leave it. If not I'll have to change some plans.
 

tdonoughue

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Part of the problem here is that between the 'smushed' fiberglass and the cracks going below the pump, you can't get a good idea of the real extent of the damage. As you note, this is a high-stress area. If you could be assured that only the gelcoat was impacted and the glass was fine, you could then surmise you had just about all of the structural integrity required (the gelcoat seals and provides that nice shine, but has almost no structural strength).

You should look inside (as @Scottintexas suggested), but you also may find yourself pulling the pump to see how bad the cracks are underneath and whether any impact on the pump damaged the glass where the pump attaches to it.

At any rate, this is something I would probably do before I would go boating again...
 

adrianp89

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I am more curious to why a new driver was driving first time at night, and why any driver would put them selves in a position to go faster than 2mph around a dock.
 

ripler

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I've had some stress cracks around those bolts for a long time and I never hit anything and never had an issue. I think its just the gelcoat cracking when the bolts are tightened.
 

Seadeals

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An easy way to check for structural damage (delamination of the fiberglass) is a coin tap test. Tap a nickel against the hull repeatedly in the areas of the damage and compare it with the sound of the similar areas on the other side of the pump or an area you know didn’t get damaged. Good glass will be a crisp tap and delam will be a distinctively different “thud”.
 

sudoMakeMeASandwich

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I am more curious to why a new driver was driving first time at night, and why any driver would put them selves in a position to go faster than 2mph around a dock.
Not a new driver per se (or night, I should have said dusk). They are very experienced around boats, just not with this particular boat. I made a judgment call that they should be fine being the DD, not realizing that jet boats behave unexpectedly different than propeller-driven boats. Lesson learned.

Our dock requires more maneuvering than most to get in. They came in slow, but sideways, panicked, threw the boat into reverse, nearly hit another boat (with the owners watching...They are mad at me now, but oh well, whats done is done), then forwards (throwing a person off the back of the boat), nearly hitting the dock then reverse again, hitting the rocks, where they finally got the sense to stop panicking and just shut the boat off. It was a cluster **** of massive proportions.

I did the coin test, tried shaking the pump, and looked at the fiberglass from inside. All looked well, however, I am still going to get it fixed, right after the 4th, just because I am a bit paranoid. Thank you all for your help!
 

tdonoughue

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Lesson learned is absolutely correct. You can't undo what is done, and it is silly to throw a friendship out over a mistake. Things happen. We learn and move on.

Sounds like you have a good plan and lots of good advice above. Let us know what the shop says on it so we can all learn from the outcome.
 

mark_m

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Not a new driver per se (or night, I should have said dusk). They are very experienced around boats, just not with this particular boat. I made a judgment call that they should be fine being the DD, not realizing that jet boats behave unexpectedly different than propeller-driven boats. Lesson learned.

Our dock requires more maneuvering than most to get in. They came in slow, but sideways, panicked, threw the boat into reverse, nearly hit another boat (with the owners watching...They are mad at me now, but oh well, whats done is done), then forwards (throwing a person off the back of the boat), nearly hitting the dock then reverse again, hitting the rocks, where they finally got the sense to stop panicking and just shut the boat off. It was a cluster **** of massive proportions.

I did the coin test, tried shaking the pump, and looked at the fiberglass from inside. All looked well, however, I am still going to get it fixed, right after the 4th, just because I am a bit paranoid. Thank you all for your help!
@sudoMakeMeASandwich Where are you located? BTW, your forum username cracks me up!
 

tdonoughue

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(for the record--got it. and love it, too)
 

Canuckjetboater

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So last night, we had a new driver driving the boat. While docking they got spooked and they backed up (with moderate speed) into some riprap (rocks):banghead:. I didn't see any obvious damage last night, and the bilge wasn't filling with water (any more than usual) so I decided to leave it in and take it out this morning.

This morning I took it out and noticed that there didn't seem to be any damage, but there are some cracks along the left side, where the impeller connects to the boat. I have no idea if that was caused by the incident last night or have been there longer, but is this something I need to worry about right now, or can it wait until the end of the season to get fixed?

Also, does anyone know of a reputable fiberglass shop in east TN or North GA?
@sudoMakeMeASandwich if your gelcoat is cracked enough to let water at your fiberglass fix it NOW - unless you want a massive repair. The resins in fiberglass with - in many cases - small amounts of uncured resin in the "sandwich" core (proper term - no pun intended based on your forum name) actually DRAW water into the fiberglass "sandwich" core. Never, ever put-off repairs to a hull where water can get past the gelcoat or barrier coat and into the fiberglass "sandwich" core unless you have a lot of $$$$$$ to burn!
 

tdonoughue

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On a normal boat, @Canuckjetboater is exactly correct. Absolutely right that the fiberglass will allow wicking of the water into the strands of the fiberglass. But, the strands are glass. And the resin is basically epoxy. Neither glass nor epoxy are going to rust in water. The issue is not that. The issue is that in most boats, manufacturers use WOOD to add stability to the fiberglass, so it does not flex as much (plus, wood is cheaper than the glass and resin). So, in a normal boat, a small crack in the gelcoat allows water to wick into the fiberglass, which hits the wood, sits on it, and BAM--you have rotted wood. And a very, very major repair.

Yamaha's, however, actually use very little wood. This has a couple of side effects. First, we have very flexible hulls (go push on yours with your thumb--you will see it flex). Second, the cracked gelcoat is not as big a deal. Now, I was told at one time that there is no wood in Yamaha--I believe I have disproved that when I think I hit wood installing my trim tabs--there on the transom. But most of the boat has no wood and elements needing reinforcement (like where the captain's chair bolts to the floor, etc.) are actually provided for by a plate of aluminum.

So, for someone with damage down by the jets, I still recommend a rapid repair. For the 'normal' ding or crack on the rest of the boat, I don't panic nearly as much.
 

Canuckjetboater

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On a normal boat, @Canuckjetboater is exactly correct. Absolutely right that the fiberglass will allow wicking of the water into the strands of the fiberglass. But, the strands are glass. And the resin is basically epoxy. Neither glass nor epoxy are going to rust in water. The issue is not that. The issue is that in most boats, manufacturers use WOOD to add stability to the fiberglass, so it does not flex as much (plus, wood is cheaper than the glass and resin). So, in a normal boat, a small crack in the gelcoat allows water to wick into the fiberglass, which hits the wood, sits on it, and BAM--you have rotted wood. And a very, very major repair.

Yamaha's, however, actually use very little wood. This has a couple of side effects. First, we have very flexible hulls (go push on yours with your thumb--you will see it flex). Second, the cracked gelcoat is not as big a deal. Now, I was told at one time that there is no wood in Yamaha--I believe I have disproved that when I think I hit wood installing my trim tabs--there on the transom. But most of the boat has no wood and elements needing reinforcement (like where the captain's chair bolts to the floor, etc.) are actually provided for by a plate of aluminum.

So, for someone with damage down by the jets, I still recommend a rapid repair. For the 'normal' ding or crack on the rest of the boat, I don't panic nearly as much.
@tdonoughue .....agree - mostly - there seems to be more wood sandwich on my Yamaha than I first thought - there appeares to be wood core "sandwich" layering on in the stern bulkhead as can be viewed when the upper swim platform hatch is removed and I could see into the cut outs to let hoses etc through it. I'll try to remember to take some pictures. I think it appears present in a lot of other areas too. Also, the wood/balsa/composite coring in layered "sandwich" hull lay-ups are the main recipients of damage from water intrusion BUT water is often, if not very often, drawn into this coring by the minute - to not so minute - amounts of uncured resin found in ALL boats - even those that have been vacuum bagged. This uncured resin draws water into the cavities like crazy. Water will even delaminate areas of mostly fiberglass of which there should be few on a boat as pure fiberglass is too heavy, brittle and not terribly strong unless it is reinforced. It would be my opinion to immediately repair any area that would be underwater or face substantial damage repairs later. If above water you have more time but why take the risk? Back in my go fast boating days we did a lot of hull modifications. I installed a number of through hull exhaust systems. Once we had cut the holes through the transoms I would sand the holes and minutely sand-bevel the edges, then wipe them down with acetone. We would let the holes dry thoroughly. Then, using my finger would thoroughly take Sikaflex and smooth it around the circumference of the holes to ensure no water intrusion before bedding the exhaust tips in more Sikaflex or 3M and wiping off the residue. Never heard from anyone of hull damage based on our/my mods/installs and that goes back to 1990. We had one rule that was carved in stone - never let any "raw" fiberglass be exposed to water. There are a few places in my 2020 Yamaha SX195 where I have seen "raw" fiberglass in areas I do not like. These will soon be cleaned and coated with marine epoxy. I have seen so many terrible/expensive fiberglass fails that were preventable I again ask - why take a chance when the cure is so simple?
 
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