Cast Iron Swing Keel Repair...Need Tips!

To all with helpful tips,

The resin and fiberglass delaminated from my iron swing keel. I have since removed all the resin and fiberglass and I am preparing to reglass. I have one specific question/concern. Do I need to replace the resin back to it's original thickness or can I just apply a few layers of fiberglass cloth and resin to keep the water from the iron? It seems as though the original glass job was a bit accessive. I would love to avoid having to apply 2 1/2 inches of resin to save time and money. If I only apply a few layers will that affect the weight and balance of my boat (1971 MacGregor Venture 22).

Thanks, Dave

 

The amount of material may have been an attempt to fair the centerboard into a shape the water likes to flow past.

Try this, after all is removed degrease with solvent type degreaser. Rough up the surface and etch with phosphoric acid. Rinse well in clean water, dry completely and apply cloth/mat set in epoxy immediately after dry. This will provide the best bond.

As to the weight issue, you'll not loose much with it not being 2 1/2" thick (some, but that centerboard weights around 800 pounds) The few pounds you do loose can be installed in a lead ingot if anyone got that up tight about it.

Question, is this a plate type of centerboard or does the casting have some foil shape to it? If you've removed all that glass and are now down to a plate, you've removed the "flying surface" or maybe "swimming surface" to the board. The plate will not perform near as well as the shaped foil would. 5" total glass (both sides) is a lot of structure to remove, and this would have to have provided some strength to the board, or else they would have done something else, cheaper. I'm not sure about the early 70's MacGregor board, as generally I avoid work on them because of the poor construction and resale value.

It doesn't make sense to cast an iron board then skin it with 5" of glass, but rarely would there be enough room in a centerboard case slot for much increase in the thickness of a board. A manufacture would try to do the shaping during the casting, not with labor. Send some photos, I have a buddy with a '72 Venture and I'll compare it with his, he wants (his wife anyway) the earth to open up and swallow it anyway.

 

Hi Dave,

If you hadn't provided your name I would have thought you were my friend Tom. The swingkeel on his Venture 22 was in the same condition as yours, with one notable exception; the steel plate was so corroded that it had swollen to the point where it had the keel jambed into the case... Three of us spent the better part of a Saturday afternoon (and not a little beer) driving it out of the centerboard casing using a one diameter steel bar as a 'hammer'.

The keel on Tom's boat was several pieces of fabricated steel plate, 1/2" thick. It appears that MacGregor used a laminated fiberglass skin (to provide the faired shape) which was fixtured around the steel, they then back-filled the void with a resin/filler mixture to encapsulate the steel ... kinda clever really (and a lot cheaper than a cast iron keel) except of course at this end of it's life span when the whole thing needs to be replaced...

Tom took the short-cut route and now regrets it. The flat plate keel makes a horrible wing.

We re-removed the keel (it was lot easier the second time) and had it sand blasted. We skinned the steel with epoxy and fiberglass cloth to protect it. Since the original fiberglass skin was destroyed we used polyurethane foam and "eyeball" estimation to rebuild the foil shape and then glassed it over with polyester and 1.5 and 3.0 oz. fiberglass cloth. I've forgotten how many laminations it was but we ended up with about 3/16" of glass over the foam. Just be careful you don't add so much material thickness that the keel won't fit back into the centerboard case.

B-I-G difference in performance. It took a lot of time to block sand, and half a gallon of bondo, to sweeten up the surfaces, but not as much as building it up all the way with resin and glass.

I've got an old Venture 17 that's in line for the same treatment...........

 

p.s...

As long as you're not trying to make any money on them, old Ventures are great little boats.... you can build them up to whatever level of performance your nerve can handle.

'course you'll never get your investment back out of them, but that isn't always the most important thing.

 

It's nice to see folks learn as hard as I did. Glad it worked out, hope the smaller version does as well. Keep sailing and enjoying them as they are the last of a breed that will not be reproduced. Good firm sailers, great for kids to learn on . . .

 

Thanks for the info.

The info you provided is much appreciated!!!

Thanks

 

Thanks Lew

Lew,

Thanks for the info. It does sound like we have the identical issue at hand. I too had to spend some time working the swollen keel from underneath. Unfortunately, I didn't have any beer on hand to help. I have the keel stripped to the iron and it is ready to be reglassed. I am going to start reglassing this weekend. It sounds as thought the most difficult part is building the volume up. Approximately how much resin was required? I am going to use woven roving and start with one gallon of resin. How thick were you able to apply the bondo?

Thanks again, Dave

 

scale plans for swing keel?? Mac venture 21

hiya folks, i am the new owner of an old boat! A'78 mac ven 21. does anyone have plans/drawings/specs on the swing keel shape?? I will do the work of figuring out how to do it, but i definitely want to be true to the performance of the original..

thanks for the help !!

Chris

 

macgregor venture 22

mine is an 82 model and the retractsble keel is iron i think it might be lead but it sure is heavy it has no glass on it it is jus shaped metal aabout 5 feet long and the problem i am having is it seems to seep water into the front settee base whre my battery is installed i think there are somekind of silicone washers in between metal ones that seal the hole for the bolt that holds it all together.. it leaks a little when i say a little i mean less than a quart of water in a 10 hour time frame in the water so it does need to be replaced..anyone know of these washers???

 

retractable keel question

Hello...we are novices who bought a fixer upper S2 23' with fixed/retractable keel..it is rusted in place, and my husband wants to glass over it and go sailing....it has a 22" draft without centerboard down...I am concerned....HELP PLEASE!!

 

Sailingchef, you should be concerned, the boat needs to have it's appendage down, not up. Talk your husband into a proper repair or capsizes could be a fairly common occurrence (keel up).

Capt. Tony, some of these had iron boards, which is what yours sounds like. Naturally, the easy way to find out is rust and a magnet. You have a pivot bolt issue, which is likely heavily corroded along with the washers, while the sealant is shot, letting in water. You have to pull the pin and make repairs as necessary once you gain access. The basics are you support the board, remove the bolt, which will resist this with it's very life, repair the flanges and landing areas, replace the washers, then reassemble, probably with a new pin too.

Chris, I don't have centerboard details. They may be available, you might have luck on one of the owners group sites. The best thing is to dig in and just sort it out. The pin bends and corrodes in time. Washers, gaskets and covers also have the same fate, so just pull it apart, clean it up and you'll have a really good idea of what it needs, which will likely be everything.

Depending on the year and board type Chris, you could improve her preformance a fair bit. This boat wasn't a speed demon, but wasn't a slug either. The board suffered from poor material and construction choices of the era, but you don't have to make the same mistakes. Primarily, shape the board so it's symmetrical and a good foil section, instead of the slab sided one of the early models.

Also note this is a very old thread (6 years), so you may want to start a new thread to address this and possibly other problems.

 

no dont glass over it get it out and fix it properly or you will get tipped over a lot trust me i had a friend with the same idea and he got wet a lot and it was never fun waiting for him with our boat trying to anchor near him and help but dam he fell over a lot(meaning his boat)

 

Thanks for the advice!!

Hello PAR...
Thanks SO much for the quick response regarding the rusted/blocked centerboard...I had trouble signing in earlier, or I would've responded before....my husband realized how much $$$ was necessary to outfit this boat, so he cut his losses and found a PY23 that is sailable for $750, so we brought it home today!!