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STV_Keith

Pro Comp Transom Problems

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What the heck is going on?  I go out of town for a couple days and get back to read about everybody's boats falling apart.  Yikes.  I'm scared to go home tonight and have a good look at mine.

I have also heard that cosmetic cracks are common but not structural ones.  I visited with a a guy the other day that has had 3 95/96 Euro's (Summerford boats) and they have all had cosmetic cracks on the transom.  

Some of the above mentioned re-enforcement ideas look really good.  Its too bad this was not from factory.

ProComp

post-2-1052405297.jpg

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NICE WORK ADAM-I like the aluminium version with a complete plate along the transom as you have done with the steel one- anyone who has a daily driver should consider doing this-as a bare minimium a plate should be used  to run from bolt hole to bolt hole- washers and nuts just do not cut it for the long run-weight gain yes-longevity increased- make your choices wisely- these photos show classic problems of stv's as they age-bytheway Wally has addressed alot of this stuff with his versions- I can think of quite a few rigs that have had the transom pulled out of them-one note-I made a very similar plate to adams out of aluminium. However, I as well made a plate that ran between the motor transom bracket and through bolted it-this in effect sandwiched the transom and pulled it back in,more so than relying on the motor bolts.

paul

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Thanks guys. ProComp, I agree that most of the cracks are just cosmetic. I'm going to keep an eye on mine though. I would have rather done my reinforcement in aluminum but then someone else would have had to do it for me.

Anyway.... good thread here.

Adam

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BLUElixir

one thing that puzzled me on your bracing is the large plates for the knees.  It seems to me that anything past the bolts is just extra mass. Why didn't you bolt it way towards the front area too? Or cut them back towards the bolts?

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It would seem that adding bolts forward would take some of the stress off the botton (floor area) and put it on the knees...assuming that's why the brace runs forward in the first place

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Yeah I had the same thoughts as you guys. When I built the brace, I didn't have a gas tank. It was on order. I wasn't exactly sure how far back the gast tank would go and how tight against the brace it would fit. As it turns out, the tank slides side to side between the knee braces so their is room. I want to add more bolts farther forward but I don't want the bolt heads to rub on the tank. I'm still thinking about what to do.

Adam

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Adam, how about notching square's into the steel and using those bolts that have the round head with the square underneath the head (carriage bolts?).  If there is room, put some thin rubber between the head and the tank.

ProComp

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The stress cracks on the rear deck of the Euro are not from the transom flexing, but from weight on the rear seat causing the deck to flex. The cracks on the curves are where the deck become ridged.

ProComp that euro transom has been painted.

As for transoms, and jackplates. The Jackplate is a lot harder on the transom, it works like a lever, consider the effect of using a longer ratchet, on a tight bolt.

Make sure that if the crack appears between the hull and the deck, that it is dried out and sealed with a good marine sealant like 3M 4200 (or 5200), the transom will rot fast otherwise.

Consider that the transom must flex a little or it will break (brittle breaks).

The STV is a well built boat, I have run the living #### out of my boats, and I have friend that have done the same, a few on this board can attest to the punishment I (we) have done to thse things. I have never had a strutural problem with a guestimated 2000 hours running time, on BIG lakes with BIG water,where the problems seem to occur it where water has become a little to friendly with the wood.

Light layup boats do not count, they will break.

RT

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GREAT COMMENTS GUYS!!!

I would suggest that any metal bracing is going to be mounted to the knees...that the connection be a slip connection and not a rigid/fixed connection.

Therefore when you drill the knees/stringers make slots or larger holes so the connection is not so rigid to induce more cracks...this time it could be a crack in your knee...allow for some movement that could result just from vibration from transom too Knee.

Also I would recommend teflon washer between the metal and the knee brace so you don't have metal wearing against the glass/wood knee brace,

And don't forget backers plates or large washers for any thru bolting!!!

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Carriage bolts aren't flush and would be a pain to install. If you want flush bolts just use flat head screws. You do need a counter sink but the large head does fine but may project through a thinner plate.

For installing through the knees I highly recommend epoxing a short length of tubing or pipe for the the bolt.

This does a few things.

The wood is sealed

Load is spread internally as well as in compression, a bolt alone only uses compression.

Easier to install and remove bolts once the tubing is in.

No more slopping rtv in the hopes it seals.

Partially an anal thing but think it's well worth the effort. The tubing is epoxied in a loose hole not a tight one.

Heres the transom, the upper holes are deceiving in that the holes weren't that big. I don't know why they look so big but weren't. On a painted surface you could do this through some masking tape and finish it all off, then remove the tape so you don't mess up the surface with epoxy slop.

!!! Gel coat can chip if drilled with a regular bit or in forward!!!

Bits for plexiglass don't chip gelcoat.

Drill a whole with some space, butter up the hole, slide in pipe. Force epoxy in the space until it oozes out the other side. Putty knife repeatedly pressing in more does it. I prefer un filled epoxy first and then cured to seal the wood hole. Then the tubing install. Like I said partially anal but works good.

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Here are some brackets that were in the inside of the above transom.

post-2-22733-Mvc_002s.jpg

That's exactly what we're going to do.  1/2" plate at the transom, 3/8" on the sides, with a 3/8" backing plate on the other side of the knee brace.

The only problem is whoever drilled the holes in my transom, the top bolts are RIGHT at the top.  IE, they had to put the nuts in, then thread the bolts into it...the nut won't turn.  The end of the bolt is actually touching the deck they are so far up.  I'm going to have to move them down to put a brace in there.  I also found that the top bolts do NOT currently have a backing plate...just a washer!  DOH!

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KEITH,

Good question on whoever drilled the holes? As far as I am told...they are done from the factory that way. As you can tell there is no way to fit a washer palte in there on the top bolts...I tried!

You could fab a custom washer palte that had stots and maybe you could silde the plate up and under the nut and bolt, with a little adhesive on the the washer palte so it would not vibrate out and fall off,

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KEITH...

So sorry to see all that misfortune you have had with our old boat...Its almost unbelievable

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The only time I saw a bot that bad was after it had a run in with a "wall of water"...can you say "Stuff"

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Keith, here is my transom from the inside.

Must be mounted lower.

Nice to see that I had a plate.  Never checked.

ProComp

post-2-1052866472.jpg

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stv keith it looks like you need to pull the top deck off yours to repair it right, its not a tuff job to do and it'll make it alot easier to repair.. use epoxy resin to do the repairs, it'll be worth it in the long run.. i spent all winter doing mine. its still withn weight and stronger then ever. good luck.

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GUYS,

I spoke with Mr. Summerford today and he confirmed that the transom mounting holes are Pre-drilled at the Factory.

The reason being is that the STV Boat requires a 3/8" lower dimension then the standard Merc Template allows.

As you aware..this is so you have some ceiling clearance for the top nuts...its not much, but it is do-able and requires a custom washer plate for the upper holes.

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Anthony, not sure what you mean. Mines looks like it had a ton of room for that upper plate re-enforcing the upper bolts.

Doesn't look custom at all.

Keith how about a similar pic from the inside at the top of yours.

ProComp

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I was only pointing out the material it was laid up with. It's a good picture since that area isn't painted. You can see it.

The only thing that comes to mind is double kevlar means it don't have the graphite in it?

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ggez, ive been out for a while  and i see this thread............sorry to the guys having problem .

 im going to look at my 89 really close today , but i can say there is no cracking near the transom at all on the exterior, ill take a look at the indside and take a pic or two and share .  mine has always had the motor bolted directly to the transom though...........i wonder if that is why some crack and some dont ?

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