E38 Chainplate U-Bolts and Replacements

[footrope]

The Navtec U-Bolts used to attach the shrouds to the deck on many Ericsons are similar to those pictured below. The original has a crack starting at the middle of the radius of the bend. I have found at least three (out of 8) that have at least one crack and the one pictured has a crack on both bends. All 8 are 1/2 inch (12mm) diameter on my boat.



As stated in other threads, RigRite makes replacements for the Navtec U-bolts. Here is what you get from RigRite for $289. And here is how they compare to the original.

 

[lnill]

on my 1987 38 I have not torn into these things yet. But I did some exploration a couple of years back. There is a company called U-Bolt-It on the internet who will custom make Ubolts out of various materials including 316. I have a quote from them 2 years ago for about $35 each. That is just the bolt, no backing plates etc and there would not be any shoulder on the bolt. I suppose you could send a picture (or actual sample) and ask if they would be able to fully replicate.
Lee

 

[Alan Gomes]

The Navtec U-Bolts used to attach the shrouds to the deck on many Ericsons are similar to those pictured below. The original has a crack starting at the middle of the radius of the bend. I have found at least three (out of 8) that have at least one crack and the one pictured has a crack on both bends. All 8 are 1/2 inch (12mm) diameter on my boat.

View attachment 15568

As stated in other threads, RigRite makes replacements for the Navtec U-bolts. Here is what you get from RigRite for $289. And here is how they compare to the original.

View attachment 15566View attachment 15567

Rig Rite's price for these is exorbitant. Garhauer custom made a set for me for my E26-2 at a fraction of the cost.

 

[u079721]

Is that $289 for just ONE? If so, it sure seems steep to spend 3% to 4% of the value of a boat for just 8 U bolts!

 

[Alan Gomes]

Is that $289 for just ONE? If so, it sure seems steep to spend 3% to 4% of the value of a boat for just 8 U bolts!

Yup. Garhauer made me a custom set for about $35 per bolt!

 

[footrope]

I didn't feel comfortable self-engineering these parts. My decision considered the performance of the original parts, the cost and hassle of replacing a mast and boom should one fail and cause that catastrophe, and the fact that these critical parts will go in the deck and will seldom be thought about unless they leak. I'll sleep just fine and try to keep an eye on them at least every year, now that I know they can indeed fail.

 

[Alan Gomes]

I didn't feel comfortable self-engineering these parts. My decision considered the performance of the original parts, the cost and hassle of replacing a mast and boom should one fail and cause that catastrophe, and the fact that these critical parts will go in the deck and will seldom be thought about unless they leak. I'll sleep just fine and try to keep an eye on them at least every year, now that I know they can indeed fail.

After reading about the many failures of these u-bolts in the forum archives, I, too, based my decision on the performance of the original parts. Looking at the Garhauer-engineered replacements I've no doubt they are superior to the originals. Garhauer engineers bomb-proof stuff. That they come at a fraction of the cost is a nice bonus.

 

[lnill]

I didn't feel comfortable self-engineering these parts. My decision considered the performance of the original parts, the cost and hassle of replacing a mast and boom should one fail and cause that catastrophe, and the fact that these critical parts will go in the deck and will seldom be thought about unless they leak. I'll sleep just fine and try to keep an eye on them at least every year, now that I know they can indeed fail.

OK, so I checked your profile and it looks like you have an engineering background in aerospace. I am a mechanical engineer but not a materials science expert by any means. I assume you read all the background posts on this topic so I would like to hear about alternatives you rejected and why. I plan to tackle this next winter when I will have to unstep the mast for other reasons. I replaces all shrouds two years ago when I refinished the mast. I visually inspected the u-bolts at that time and was somewhat concerned but did not take it on at that time due to time constraints. But given that mine are 28 years old I probably don't want to delay much longer.

 

[footrope]

lnill,

I wish you good results on the u-bolt inspection. I should have done my inspection sooner but I wasn’t expecting to find a problem. Ten years ago I had pulled out the starboard u-bolt pair (for the cap shroud and intermediate shroud) because they needed to be re-bedded. They were ok then. The picture I posted at the start of this thread is of the inboard one. So the cracks showed up over the last 10 years. The cracks are not covered up by the fittings, either. I can send you higher resolution pictures of the cracks in the bend radius if you PM me your e-mail address.

You'll probably have to clean up the bends to get a good look. Also, the u-bolts need to come out of the deck so you can take a look at the threads and the underside of the shoulders and get a better look at the underside of the bend radii.

 

[lnill]

lnill,

I wish you good results on the u-bolt inspection. I should have done my inspection sooner but I wasn’t expecting to find a problem. Ten years ago I had pulled out the starboard u-bolt pair (for the cap shroud and intermediate shroud) because they needed to be re-bedded. They were ok then. The picture I posted at the start of this thread is of the inboard one. So the cracks showed up over the last 10 years. The cracks are not covered up by the fittings, either. I can send you higher resolution pictures of the cracks in the bend radius if you PM me your e-mail address.

You'll probably have to clean up the bends to get a good look. Also, the u-bolts need to come out of the deck so you can take a look at the threads and the underside of the shoulders and get a better look at the underside of the bend radii.

The more I think about this the more uncomfortable I get. We don't race or anything and I am a pretty conservative sailor but the thought of one of those things giving up is pretty scary!!! My boat has been well cared for and is a few years newer than yours but it is probably time.

 

[Shelman]

cast vs machined?

On the rigrite website they talk about these Navtec U-bolt chain-plates and they mention that the older ones made by Navtec were cast and then Navtec changed to machined U-bolts. I wonder how many of which kind we see pictures of here. some boats really seem to have troubles with them and some dont. I also wonder about how the bent (cold forged) from Garhauer compare. Does cold formed (bent) mean cast? extruded? machined? I'm looking into whether there seems to be any correlation between year of manufacture and cracking which would lead me to believe the old cast design had issues.
Or is it there some other issue that causes some to fail and some to last. perhaps its just like the rest of the standing rigging, after ten years your on borrowed time. I have removed mine and inspected them but I still feel they are too old to scratch off my list.

 

[Shelman]

found more info here

http://www.ericsonyachts.org/infoexchange/showthread.php?10836-Ericson-30-chainplate-U-bolt/page2

yep seems the newer style $300 ones were cold formed around a die so im guessing that having some bent by a good machine shop would be similar.

 

[Alan Gomes]

On the rigrite website they talk about these Navtec U-bolt chain-plates and they mention that the older ones made by Navtec were cast and then Navtec changed to machined U-bolts. I wonder how many of which kind we see pictures of here. some boats really seem to have troubles with them and some dont. I also wonder about how the bent (cold forged) from Garhauer compare. Does cold formed (bent) mean cast? extruded? machined? I'm looking into whether there seems to be any correlation between year of manufacture and cracking which would lead me to believe the old cast design had issues.
Or is it there some other issue that causes some to fail and some to last. perhaps its just like the rest of the standing rigging, after ten years your on borrowed time. I have removed mine and inspected them but I still feel they are too old to scratch off my list.

Hi, Randy! Why not give Garhauer a call and ask them about it. The U-bolts I had them custom make for me are essentially the same as what they sell in the retrofit kit for the Catalina 27. (Catalina Direct sells the kit; you can see a picture here: http://www.catalinadirect.com/index.cfm/product/12_45/chainplate-u-bolt-retrofit-kit-c-27.cfm). Were it not for the fact that the leg spacing on their off the shelf U-bolts was just slightly too wide, I would have gone with those rather than having custom ones made. By giving them the old ones to use as a pattern they were able to fabricate drop in replacements.

 

[Shelman]

Garhauer

Alan,
I emailed Garhauer today to inquire about them. thanks for the reminder. Did they have the flat top like the originals? or were they rounded on top?
I really wanted to do my research on why there were so many odd failures and if it had anything to do with material. I think its probably more due to being past the life expectancy of the u-bolt in the first place. Cold formed seemed to be the original manufacturing method so it looks like they would be as strong as the originals.
I thought I might even go over over sized but I don't think its necessary especially on our little 26

Thanks.

 

[Alan Gomes]

Alan,
I emailed Garhauer today to inquire about them. thanks for the reminder. Did they have the flat top like the originals? or were they rounded on top?
I really wanted to do my research on why there were so many odd failures and if it had anything to do with material. I think its probably more due to being past the life expectancy of the u-bolt in the first place. Cold formed seemed to be the original manufacturing method so it looks like they would be as strong as the originals.
I thought I might even go over over sized but I don't think its necessary especially on our little 26

Thanks.

Randy,
I don't remember exactly what we decided to do about the shape. If I recall, they are less rounded than their Catalina 27 retrofit U-bolts but less square than the originals. I honestly don't remember for certain, but I can snap some pics if you'd like.

 

[Shelman]

pictures

Alan,
That would be great! thank you.

 

[Alan Gomes]

Alan,
That would be great! thank you.

Ok. I'll make a note to do that next time I'm at the boat--probably this coming Friday.

 

[Shelman]

Anybody thought of doing a conversion from the U-bolts to something more like this?

 

[footrope]

If a man answers the phone at Rigrite ...

Don't hang up.

I learned today that the six (overpriced, questionably constructed) 1/2" u-bolts that were back-ordered from Rigrite in mid-December should be back from polishing any day and will ship immediately when they arrive. I went in to the Sales/Part Ordering choices on their automated system and the man that answered was very pleasant and immediately helpful. That is the first time I have had someone other than the uninterested woman answer a call there.

Don't get your hopes up.

Today I will continue my efforts to get the old ones out of the aluminum blocks. I'm only 1 for 5 so far and dying a slow death working on the corroded aft starboard fitting. Once I get the new ones in hand I'll start cutting the "U" section above decks so I can put a wrench on and unscrew them from the corrosion.

(Note: The first two new ones I ordered were in stock, shipped about a week after I called, and took a week to get to the west coast. They arrived Jan 2nd.)

 

[Shelman]

removing u-bolts

One little secret to removing the U-bolts from the inevitably corroded aluminum blocks on the underside of the deck is to over tighten them just enough to compress the plywood core and break the bolts loose. then they come out pretty easily.