Stanchion re-work

We just finished overhauling all the stanchions on our Gulfstar 36 trawler. Several of them leaked, especially those directly over the bunks (of course). I was disappointed to discover that they were not properly installed from the factory 39 years ago. I have fiberglass decks with 1 inch balsa coring. NONE of them had been strengthened to transmit forces to the back up plates. Hardware was just through drilled, and finished with a fiberglass back up plate, lock washer and nut. Over time, stress on the stanchion worked on the core, collapsing it and allowing water entry. And you know what happens when water gets to the balsa. Several POs over-torqued the leakers, and smeared some miracle anky-poo on it to fix it. I undercut the mounting holes, filled the void with epoxy, then redrilled the holes and installed with Boat Life caulk. Oh yeah, covering the bottom of the holes before pouring the epoxy is another story. It's in the blog. The entire process took 9 days to complete, though some of the time was waiting for the epoxy to kick. We put a commentary and pictures on our blog site. Heck of a job, but at least now it is right and won't leak. Now on to re-bedding the ports and windows.

Greetings,
"Oh yeah, covering the bottom of the holes before pouring the epoxy is another story." I suspect it's along the same lines as put your fitting on BEFORE you flare the tubing....

Oh I covered them, alright. But blue painter's tape doesn't work too well. (sigh). "Don't worry, honey, you can buy some new sheets for your bunk now!" Should have manned-upped and used Duct Tape to begin with!!

Bilgewater said:

Oh I covered them, alright. But blue painter's tape doesn't work too well. (sigh). "Don't worry, honey, you can buy some new sheets for your bunk now!" Should have manned-upped and used Duct Tape to begin with!!

Click to expand...

Thanks for the info! I had similar project recently. The mounting for the ladder from the swim deck on our Sundeck had one side that had gotten very loose. After removing the screws I found about 2" of empty void below. No wood at all. I tried several approachs to contain the epoxy when I was ready to pour West into the now oversized hole. What I ended up doing was spraying an insulating expanding foam I purchased from WM and then drilling out a "mold" to hold the epoxy. Worked like a champ and I'm sure any expanding foam would work.

Bilgewater said:

Oh I covered them, alright. But blue painter's tape doesn't work too well. (sigh). "Don't worry, honey, you can buy some new sheets for your bunk now!" Should have manned-upped and used Duct Tape to begin with!!

Click to expand...

I've used modeling clay.

If you are reglazing the windows, I recommend Sika 295UV....its a little messy, but the stuff is great, and it does not succumb to UV from the sun.... I reglazed our windows on our GulfStar 44 with the Sika....and we are in Florida...it has held up well through two summers with no chalking or bleeding.....

Our boat had Atkins Hoyle ports in it, and 3 deadlites at the stern...replaced them all with New Found Metals Tri-Matrix Portlights....that are "self-sealing" when installed per instructions and the price is right. But if you choose to rebed....have you ever worked with 3M 4000UV? Good stuff.

Thanks for that info. I've been slowly doing each stanchion and experimenting a bit with different techniques, depending on how much (if any) rot in the end-grain balsa core. So far however, I've had my best luck with butyl rubber tape for bedding.

I had a new aluminum mast make last year and increased the size of the stanchions from 2” X 6” to 10” X 14”. A new stronger mast was required as the first step for fish stabilizers and additional stanchions will have to be added.

When using the foam make sure you do not over fill as the foam expands. Big mess, and new problems!

I was reading an article about this sort of repair.

It called for using a bent nail or an Allen wrench and a drill to sort of warble out a cavity between the inner and outer surfaces. Then filling the cavity with the epoxy then to re drill the hole for the screws.

Has anyone done similar?

Exactly, Skipperdude. There are several places I found minor rot in a larger circumference below the bolt holes for the stanchion bases. I hate it, but if you don't repair the area around the hole, the bolt will simply compress the area and crack the glass above and below when retightened. Sometimes it's difficult to seal underneath when pouring in the epoxy. Of course, it helps to have some dry weather too.

SD

Yes but I used thickend epoxy.

skipperdude said:

I was reading an article about this sort of repair.

It called for using a bent nail or an Allen wrench and a drill to sort of warble out a cavity between the inner and outer surfaces. Then filling the cavity with the epoxy then to re drill the hole for the screws.

Has anyone done similar?

Click to expand...

Yes, I did this in the spring. Used wooden bungs hammered in the holes to hold the epoxy.

Skipperdude - the bent nail was the method I was using for all but two of the stanchions. A little tedious, but it works. Sometimes I had to start with the bent nail in a vise grip to break up the balsa. Other times, the drill did fine. Then used the shop vac and tweezers to clean out the debris. You have to be careful when starting not to rock the nail back against the deck and chip the gelcoat/fiberglass. Easy to do with the mechanical advantage available. It helped to be on the hard working from a scaffold at a comfortable height. I'd hate to have to do it on my hands and knees from the deck. Getting old sucks!.

The methods for deck repair high load fittings like a stanchon are simple.

Usually the outer skin gets damaged as the core is crushed by the small area of the base .A good blocking plate BELOW does not avert the damage.

Our way of repair is to epoxy a 1/4 to 1/2 inch laminate to the broken part of the deck, which is larger by at least an inch than the base plate.Grind clean for secondary bonding.

A 1 1/2 or so hole is drilled thru the deck ,and rotten core , but not thru the inner skin directly under the high load fitting .Thickened epoxy will fill the hole and stick the deck plate and can take the compression better than light weight core.

When assembled this will mount stanchons , or the harder Davit mount points (bigger base , more holes) that will not tear out.

The added height off the deck of the sealant will help with leaks.

FF

healhustler said:

Thanks for that info. I've been slowly doing each stanchion and experimenting a bit with different techniques, depending on how much (if any) rot in the end-grain balsa core. So far however, I've had my best luck with butyl rubber tape for bedding.

Click to expand...

So far I've been lucky...not having any balsa cored decks or hulls....

The windows on our trawler appeared to have been bedded with some type of rubber tape...I'm not sure if it was butyl or not, but it had been there awhile...and it was really nasty.... It had formed a few bubbles, and the surface was very chalky...if you brushed up against it...you got black on your clothes that was hard to get out, and if you got it on skin...not easy to wash off, and with a heavy dew or rain...it left black streaks on the outside of the salon and on the deck....

I had to reglaze all of the windows on the boat and I went investigating and found that the 295 UV was a very reliable sealant to use that was UV resistant and would not chalk or leave streaks....so far...after more than a year...it has performed as claimed.

FF...our Manatee has lived under cover since 2003 & our surveyor in 2011 found no soft spots in the decks or elevated moisture readings but suggested that before we expose her to the elements I should rebed all the stanchon bases as you & others suggest.

If using West systems, what thicken agent do you suggest?

Also, you mentioned adding a 1/4 to 1/2" laminate to the deck...is that something I would make or is it available in sheets to shape as needed?

Philip

Also, you mentioned adding a 1/4 to 1/2" laminate to the deck...is that something I would make or is it available in sheets to shape as needed?

Go to an active boat yard and look in their scrap pile.

A thick piece of removed deck , or a hunk of transom is great.

If the process wont take place till after 1 Nov I can send a hunk, for the cost of postage.

West filler , you want what will be stiffest .

Epoxy is strange , mix the stuff , add the filler , wait a few min and add some more.

This sometimes can be done 3 or 4 times .

Should be like chocolate syrup, not peanut butter , so it will flow as you put it into the cavity.

FF

Last year we spent weeks doing exactly what you did to every deck fitting on our sailboat - cleats, stanchions, winches. A lot of work but worth it. I did use lots of duct tape to cover the bottom of the holes. I also used new hardware when we reinstalled. To seal the hardware, we used butyl rubber and it is holding up really well. I'd also add that having added the thickened epoxy and larger backing plates made a huge difference. Long story, but last July our boat and a friend's powerboat sustained damage during a freak storm. One of our stanchions wound up going through his hull below the rubrail where the bow begins to flare. The stanchion wound up bent over 90 degrees, but the deck at the base didn't even get a stress crack in the gelcoat. I'm a firm believer in potting any holes in a cored hull and using oversized backing plates. It is a lot of work to do after the fact and too bad that very few manufacturers do it from the factory (I think Hinkley is one of the few and, of course, you pay for that kind of quality).

cabosil is ground up fiberglass. Like a power only finer

colloidal silica thickener.

Mix it with the epoxy.

SD

I also use thickend epoxy but also played with GitRot wood conditioner in a few areas. Seems like a great idea to use a top plate like FF suggests. I think I may begin doing that, especially in areas where greater leverage could occur. It would have to be done right to leave a good impression. Question to FF though. Do you use the 1 1/2" drill hole universally at each hole at the base, assuming of course that there is rot to be fixed?

Do you use the 1 1/2" drill hole universally at each hole at the base, assuming of course that there is rot to be fixed?

Usually I use a 1/4 over sized stiffener epoxied to the deck , and then a single 1 1/2 plug works fine.

Where an owner does not like the "look" of the added plate , I prefer a 3/4 hole for each thru bolt and a center plug of a size that looks OK. All holes are epoxy filled and redrilled.

Since we will not attempt a gel coat match , this is as good as can be done.

Sometimes the GRP pad can be hidden with a teak pad and is OK with the owner.

For a deck mounted davit , we will epoxy the GRP plate in then lay up a GRP laminate on top , as the loads of a dink full of rain is high..