Strut bolts

[GaryNW]

Nothing earth-shattering here, but I see it's a slow day at the forum...so-
I received my new strut from Sam's for my 31' EC. No real hurry on the haulout as the existing bent and twisted unit is a fuel consumption issue, not a structural or safety issue. I will be collecting the stuff I need at the haulout now- such as new PSS seals and STRUT BOLTS.

Question to those who have removed struts/bolts from their Hatteri. Did the factory use flat-head or oval-head bolts? I see some marine bolt suppliers speak to "strut bolts" and these are oval-head. These same suppliers have flat-head bolts in the same silicon bronze alloy as their "strut bolts". No significant price diffy, however my local joint has the flat-heads on the shelf for the right price but would have to special order the ovals. So what have you folks found when you removed the factory bolts?

Related question. How difficult to break loose the factory sealant? Did the factory use 5200 or something less ruthless? I am thinking of using a torch if they used 5200. I don't want to destroy layers of roving getting this thing off.

FYI- the new strut came predrilled and countersunk for the 1/2" bolts.

Gary

 

[REBrueckner]

Use the flat head if you can get them at a good price...it makes no difference except: Select flat head if they have a slot to hold them from turning during installation....the important thing is that they are the same metal as the strut, likely silicon bronze as you posted, and that the underside taper of the head fits smoothly to the taper of the strut hole....or flat to flat surface if that's the style...(not as desireable)

if the current strut can be run ok, sounds like the twist/bend is minor...if so it can likely be straightened...often right in place....

 

[GaryNW]

Thanks for the input. All of the flat-heads and oval-heads I am seeing are slotted. I assume the old bolts are too but haven't verifed for all the sealant and bottom paint. Yeah, I plan to carry the strut in the store to verify the countersink fit. I suspect everything to be a std 82 degrees.

Castings (struts, logs, rudders) tend to be yellow when new- a color we usually identify as "brass". Bronze bolts are brown and obviously a different alloy. This combo has been the std for years so I am not concerned. I am leary of Chinese fasteners based on some horror stories.

I thought about straightening the strut- even in place but decided to bite the $950 bullit and go new. With a flow time of over a month for a new strut, the haulout becomes excessive if the straightening goes south. I will look to having the old strut refurbed off the boat as a spare. Nice thing is that my port and stb are the same part#.

Gary

 

[Nonchalant1]

I believe Hatteras used something more stiff than 5200 when installing the struts at the factory. Of course, yours could have been off between then and now. I was able to break the rudder shaft thru hulls loose with a 1 inch wide, sharp, flat blade woodworker's chisel. The sealant was a white, very hard substance, almost like white MarineTex. After taking the bronze nuts off the bolts, I backed the bolts out of the bronze thru hulls by unscrewing them with a big flat blade screwdriver. They were put in at different angles, so you can't pull the fitting off with the bolts in place. The bolts have to come completely out first. Then, I put the flat side of the cutting edge of the chisel against the metal of the thru hull and hit it with a hammer until the bronze fitting came off.

I examined the white compound where the fitting went and found that it was very hard and about 1/16th inch thick. I cleaned and sanded it all around the edges and found that it was the same color and consistency as the rest of the bottom there and was like a built up platform that the fitting fit on. I wanted the fitting to be put back at the same angle and depth as before, so I left that white platform in place, slathered everything with 5200 and bolted it back in place with the original flathead bronze bolts. It has held perfectly for 3 years, no changes, no leaks, still looks perfect.

Doug Shuman

 

[buzzk]

I had a 34 that had to have a strut taken off and replaced. The factory on my boat used some kind of hard epoxy to shim my strut and then used a soft material like 5200 to bed it in. Buzz

 

[Maynard Rupp]

Don't screw up the liquid shim. In order to allign a strut, the builders use a thick epoxy filler between the strut and hull. They tighten the bolts just enough to get the strut straight and alligned with the shaft. The excess oozes out annd they wipe that and let the stuff cure. Now they use a caulk between the epoxy build up, (shim), and the strut. Now they tighten the bolts. Don't dig the shim out or you will have to re-align the whole mess.

 

[GaryNW]

Sounds pretty much like what I was expectng. A hard compound to establish alignment, then the srut is removed and a flexible sealant is applied. I expect to have to re-apply some hard stuff as the new strut was not machined flat on the base. One corner is a little thin and a straight-edge confirms that this area is low. I don't understand why they had difficulty simply creating a flat plain unless the casting was thin on this corner. Not enough of a problem to reject the part I suppose. I figured the replacement would not just produce perfect alignment right out of the box.
thanks for the inputs!
Gary