Repairing Fiberglass Stress Crack

[pgbrown]

Great News ! They folks at Arima :applause: are the best

[GregE]

Good to hear!!

I met Belinda a couple times at the Auburn Arima shop.  Her guided tour of the facility pointing out the construction methods really helped understand how Arimas hold up so well.

[BayWolf]

Just curious. Did Don recommend a fix for the motor mounting which may have caused the cracking?  I'm sure your not going to keep that block under it?

[croaker stroker]

Whether a new installation or repower, my shop always uses a 1/4-3/16 thick aluminum backer plate between engine mount and transom....this provides a sound base ...covers caulked (5200) old holes and would eliminate engine mount from resting against transom trim.
Doo Dad

+1

....or trim the molding.  Either way, the motor needs to be dismounted.

[Hunter]

Whether a new installation or repower, my shop always uses a 1/4-3/16 thick aluminum backer plate between engine mount and transom....this provides a sound base ...covers caulked (5200) old holes and would eliminate engine mount from resting against transom trim.
Doo Dad

+1

....or trim the molding.  Either way, the motor needs to be dismounted.

Not according to Don and Belinda..  As a matter of fact, when I asked about how best to fill or seal the crack, here is the exact answer I received....

Don actually had a couple of suggestions.  There is no need to fill.  With the aluminum transom cap you have, add our new black plastic trim over the edge to cover or with more work, remove aluminum trim and replace with black transom cap and also put the another one over the edge (just like with the aluminum).  The next email you get from me will show 1) new boat with vinyl transom cap, 2) New boat with new transom cap with the second piece put on to cover an inch below the other cap, and 3) a piece of the transom cap from a back view.

Also... I guess another question is...... Does Arima use an aluminum plate on new... or repower installs?   If not, why not? 

I admittedly don't really know any of you folks on this forum.... so as convincing as some folks might sound,  I'm naturally more inclined to go with the advise of Belinda and Don.   

[Markshoreline]

I'm curious about what the crack was caused by and how significant is it and how to resolve it.  What issues may occur because of it's original creation?

How does putting a black cap on it resolve whatever the problem was?

Maybe this advice is just saying that it is a normal thing and the cap will keep you from looking at it?  However, I'm still curious about why it's there...there's not one on my boat and I haven't seen it before in my years on this forum.

[croaker stroker]

Whether a new installation or repower, my shop always uses a 1/4-3/16 thick aluminum backer plate between engine mount and transom....this provides a sound base ...covers caulked (5200) old holes and would eliminate engine mount from resting against transom trim.
Doo Dad

+1

....or trim the molding.  Either way, the motor needs to be dismounted.

Not according to Don and Belinda..  As a matter of fact, when I asked about how best to fioll or seal the crack, here is the exact answer I received....

Don actually had a couple of suggestions.  There is no need to fill.  With the aluminum transom cap you have, add our new black plastic trim over the edge to cover or with more work, remove aluminum trim and replace with black transom cap and also put the another one over the edge (just like with the aluminum).  The next email you get from me will show 1) new boat with vinyl transom cap, 2) New boat with new transom cap with the second piece put on to cover an inch below the other cap, and 3) a piece of the transom cap from a back view.

Also... I guess another question is...... Does Arima use an aluminum plate on new... or repower installs?   If not, why not? 

I admittedly don't really know any of you folks on this forum.... so as convincing as some folks might sound,  I'm naturally more inclined to go with the advise of Belinda and Don.

Glad to see you got it resolved.

[Yachter Yat]

Kinda what I said............cover it.   Only thing is, some kind of sealant (like Lifeseal) might be advisable.

Yat

[Hunter]

Thaks for everyones help and advice.  The crack is not a problem.  It is cosmetic only.  How it happenned is no longer a concern to me.  The general consensus is that torqing the mount clamp against the aluminum trim cracked the gelcoat.  It is amazing what you can do with Macro camera shots these days so I can say that the crack has been thoroughly examined.

Any, I'm down to two options of what I'm going to do.  Both options will include me dremeling out the crack to mor workable "V" shape and filling with Marine Tex.... or possibly even some color matched gelcoat that Belinda can get her hands on for any year Arima.  Both options will utilize the new black vinyl transom cap trim that Arima is currently using on all new boats instead of the aluminum cap that is on my boat.  The trim is simple "L" with 1/2 in on the short leg and 1 in on the long leg.   Belinda is shipping it to me today.  $20 for all I'll need including the shipping.  "THANKS BELINDA!!!!!"

Option 1...... Suggested by Don is to simply apply the new trim right over the aluminum cap with the short leg on top and the longer leg to cover the crack.   Not sure how that will look, but it'll be easy enough to find out before attaching.

Option 2...... Remove the wood block and loosen the mount bolts just enough to completely remove the old aluminum cap altogether.  Then apply the new vinyl trim with the long leg on top and short leg over the edge..  Then apply a secon piece of the same trim with the short leg on top and the long leg to hide the repair. 

Here's some factory pics sent by Don and Belinda..

[croaker stroker]

Unless I'm not understanding your explaination, neither solution addresses the problem of the motor bracket mounted on top of the trim molding. (As MarkS pointed out)

Judging by the crack, your bracket has moved (loosened) since it was installed. JW's observation of the "extra" upper mounting bolt is evidence that someone was trying to "fix" that problem.

Your bracket will never be truly tight unless you either remove the molding from under the bracket, or shim your bracket away from the molding (Aluminum plate was suggested), allowing your bracket to be flush and tight against your transom.

This is my opinion. Take it...or leave it.  You are not the only one with this problem.

[BayWolf]

So, the motor was raised leaving the top edge of the mounting bracket free floating (well, a block of wood shoved under it)?

For my education, why would a motor be mounted like that?  I can't recall ever seeing something like that.  Seems like it would put an awful lot of downward stress on the mounting bolts?

Always learning.  Thanks.

[croaker stroker]

The cavitation plate of the motor needs to ride on top of the water. If, when your boat is on plane, your cav. Plate is under water, then it needs to be raised for max performance.

Not sure why?  Remember the Arima transom has to fit all motors. Better to make the transom too low than too high.

[ak-angler]

The motor isn't supposed to sit on the transom, or on a block of wood that sits on the transom. The bolts are plenty strong enough in shear to support the weight of the motor. The vast majority of bolt-on (as opposed to clamp-on) outboards are mounted this way.

The issue in this particular situation is the thickness of the transom cap trim, and how it interferes with the 'flats' on the motor mount brackets. I thought I was going to run into the same issue when I installed my DF90A. In my case, it ended up being a non-issue, as there was just enough clearance to snug everything up with the anti-ventilation plate at the height I wanted without the motor mounts actually touching the trim piece. But, any higher, and I would have had to install a spacer plate to set the motor back about a quarter of an inch.

[croaker stroker]

AK, ....you've got a nut loose.   

That's a good pic to show the issue.

[ak-angler]

 


Ha! That picture was, of course, taken during the installation process. At this point, I believe that the only loose nut on the boat is the one that connects the steering wheel to the helm seat.

[BayWolf]

Got it!  Thanks!

Always learning.

[Wyrguy]

AK, ....you've got a loose nut.

That's a good pic to show the issue.

Rick


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[croaker stroker]

No disrespect unintended.    :arms:

[Hunter]

The motor isn't supposed to sit on the transom, or on a block of wood that sits on the transom. The bolts are plenty strong enough in shear to support the weight of the motor. The vast majority of bolt-on (as opposed to clamp-on) outboards are mounted this way.

The issue in this particular situation is the thickness of the transom cap trim, and how it interferes with the 'flats' on the motor mount brackets. I thought I was going to run into the same issue when I installed my DF90A. In my case, it ended up being a non-issue, as there was just enough clearance to snug everything up with the anti-ventilation plate at the height I wanted without the motor mounts actually touching the trim piece. But, any higher, and I would have had to install a spacer plate to set the motor back about a quarter of an inch.

This post and picture by AK explains the issue of the "crack" exactly.   IF.... AK's bracket had been just slightly higher, it would (could) have pressed against the trim and casued the crack.  It also explains why in most installs.... none of the motor or bracket is bearing on top of the transom.     Thanks for that pic AK..... much better than the one I posted.   

[dbhazjack]

It would appear that the mounts are designed for this reason in mind!



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[Wyrguy]

Hunter, maybe comparing a SL 22 to an SL 22 might help??? Here's how my 250 Yammie is mounted:



Also, before Arima was merged with Defiance, none of the boats were rigged by Arima. It was the dealers mounting the O/B's so you're going to get a whooooole bunch of different combinations!!!

(Not my boat, but showing the two bottom bolts shipped from the factory in a 19' SR)



My dealer hung my 250 off of the bottom two bolts then adjusted the height to ensure the anti-ventilation plate (commonly miss-labeled as an anti-cavitation plate!) was level with the bottom of the hull. That's when the upper two bolts were then placed and tightened.

Rick


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[LvrWurst 21 SR Skip]

Refresher Course about OB Motor Mounting Height:
My 2 cents...a shim plate mounted between OB Bracket & Fiberglass Transom would have eliminated this cracking issue.
Respectfully submitted: J. Doo Dad

"What determines best position for mounting outboard motor?
http://www.thehulltruth.com/boating-forum/76306-outboard-mounting-height.html
"We hang alot of Suzukis they want the plate 3/4" above the bottom. You do not want it below the hull or when you are on plane it will spray water up the transom."
TIPS:
The overall height of an outboard motor from the top of the housing to the bottom of the skeg is not important. The only height measurement you need to worry about when selecting an outboard for your boat is the height of the shaft. If the shaft is too short, the propeller will lift out of the water when the boat is on plane. If it's too long, the additional length creates drag under the water and limits the boat's top speed.

Read more: How to Determine Outboard Motor Height | eHow.com http://www.ehow.com/how_7833867_determine-outboard-motor-height.html#ixzz1oMVoBUz6

1
Measure the distance from the top of the transom to the bottom at the tallest point.

Read more: How to Determine the Mounting Height for an Outboard | eHow.com http://www.ehow.com/how_8072136_determine-mounting-height-outboard.html#ixzz1oMVSruFu
2
Measure the outboard from the top of the mounting clamp to the bottom of the anti-ventilation plate. This will tell you the shaft length on the motor. The plate should be level with the bottom of the boat.
Read more: How to Determine the Mounting Height for an Outboard | eHow.com http://www.ehow.com/how_8072136_determine-mounting-height-outboard.html#ixzz1oMVLvTJp
3
Calculate the difference in the motor's shaft length compared to the boat transom. A boat with a 20-inch transom being mounted with an outboard that has a 21-inch shaft length should have the motor raised by one inch.
Read more: How to Determine the Mounting Height for an Outboard | eHow.com http://www.ehow.com/how_8072136_determine-mounting-height-outboard.html#ixzz1oMVFvF1M
You can adjust the height of the motor for better performance. If you raise the motor so the ventilation plate is above the bottom of the boat, the boat will have better stability and higher speed at the cost of control torque.
Read more: How to Determine the Mounting Height for an Outboard | eHow.com http://www.ehow.com/how_8072136_determine-mounting-height-outboard.html#ixzz1oMV546pf
Most outboard manufacturers have recommended mounting heights listed for their motors. Check with the manufacturer to see which motor best fits your boat.
Read more: How to Determine the Mounting Height for an Outboard | eHow.com http://www.ehow.com/how_8072136_determine-mounting-height-outboard.html#ixzz1oMUxcvL6
The outboard must be mounted high enough so that the exhaust hole is not underwater. It should be at least one inch above the water line at idle speed.
Read more: How to Determine the Mounting Height for an Outboard | eHow.com http://www.ehow.com/how_8072136_determine-mounting-height-outboard.html#ixzz1oMUlVuaD

[Wyrguy]

CS, I've sent you a PM now that you're question to me here has been deleted... :-(

Rick


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[croaker stroker]

CS, I've sent you a PM now that you're question to me here has been deleted... :-(

Rick


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Sorry, here it is again, for the benefit of others....

"Wyrguy,

Looks like yours is shimmed out using indiviual spacers.  I was thinking of two slotted shim plates so they could be slipped in from the side without dismounting the motor.

Or is that just an optical illusion ??"

[Hunter]

Not sure of anyone is still interested in this old thread..... but after looking at my crappy seal job on this "ass crack", I finally decided to bite the bullet and just have it done right.   Ryan at Performance Marine at Everett did the work and the color match on the gelcoat.  The pics here don't do his work justice.  His work is a spot on match and perfect.  I was also able to get a few other dings and some old transom holes taken care of.    Total cost, including the R & R of the Suzi 250 was $900.....  but now it's done right and good as new!