Swan 38 replacement of galvanised steel frame Dear Lars,
As you may have guessed, I am taking my Swan 38 apart this winter for in depth maintenance! After a marine surveyor’s report we found that the galvanised steel frame has badly rusted under the mast step stainless steel shoe and will need to be totally replaced. The question we have is can you remove the frame without cutting the main bulkhead and head compartment? It seems impossible to do without cutting up the interior which is a shame.
We will fabricate the new frame in stainless steel – was there any reason that you originally used galvanised steel frames?
What torque should we do up the bolts and keel bolts to? Is there anything else that we should be careful of?
Best regards,
Patrick
PS I notice that on the G Frers designed Swan 46 the frame can be removed without major open heart surgery http://www.swan46.org/maintenance/twilight-galvanizing-of-steel-frame/
Dear Patrick
As far as I know the steel frame can not be taken out without cutting up parts of the interior, and possibly also requires an enlarged opening in the deck.
The same refers for getting the new one in.
I would suggest a different approach - cut the frame into pieces that easily come out, and make the new frame of G-plate enabling it to be glued together inside the boat. This has been done on a few larger Swans.
G-10 glass-epoxy composite is a strong material which can replace steel here, and does not corrode. Apparently not a well known material in the UK, googling did not bring up any supplier there.
If you could send me a few pictures of the frame and confirm the present plate thickness a G-10 structure with equivalent strength and stiffness but considerably lighter can be conceived.
Using stainless AISI 316 is not a good idea, pls note that the thickness has to be increased 1.8 times for equal strength, and the welder must be aware of the risk of weld decay with this material, and there is unavoidable weld distortion causing warping.
The forward keel bolts are all M24, recommended torque 190 lbsft with threads ungreased.
Kind regards
Lars
Different boat, same problem -- we will have to address the frame corrosion as well, so I am looking forward to knowledgeable input ...
Best, Martin
Age of Swan (48/039)
Many Thanks Lars,
G-10 sounds the logical route. Do You know if anyone can make a kit up from the original Swan 38 plans or will we have to make up a template from the (remains) of the old frame? You mention a yard that has done this before on larger Swan's as we could do with their expertise and experience.. David Heritage in Cowes is pretty good with composites but he will need some help and advice as no one has done this before in Cowes.
There must be many more classic Swans whose frames are nearing the end of their natural life so am suprised somone has not made a business out of fabricating replacement kits or is each Hull slightly different? I enclose a Pic taking in 2008 of the corrosion.
Best regards,
Patrick
Any more update on the work you are doing?
I am doing exactly the same thing on my boat. It has been so far an extraordinary amount of hours spent cleaning, grinding, sanding etc... full of great learnings.
The last phase will be sand blasting the structure frame.... then refinish... Would love to share your experience...
This happen to be a lot of more work than anticipated... Is not it always the case????
Will post some photographs.
Vincent
38/106
HI Vincent
I really wish I could give you some info' but the boat builder on the Isle of White has only now just started costing the works/thinking about it, despite Lars kindly offering him advice on how to do it with G10 before Xmas!
It looks like this will now not be done this year. I would like any suggestions on where I can get this work done - I am willing to sail the boat up to the Baltic if necessary to avoid being disappointed again by pedantic English boatyards.
If there is a miraculous turn around on the IoW I will send you the details of how we did it but I would not hold your breath!
Fair winds
Patrick
Hi all,
we are facing the same problems on our 48, and we have decided to replace the corroded part of the steel frame by a new galvanized steel frame insert. We did consider G10 but found no one here who had any experience with the material so we went with the steel.
I am posting the procedure on a thread started earlier this month in this forum, titled "G10 or G11 on a mast foot", just to give you a cross-reference.
Fair winds and strong frames for all of us,
Martin (Age of Swan, 48/039)
Thank you for the feed back.. Sad you got yourself in a non progressive situation..
With recommendation from Lars when I discovered a "leak from the keel" I decided to take on this project myself... Not easy for sure... I am doing all the cleaning prep sand blasting etc...which I never done before.... as I was so disappointed with the work done by Jamestown Boat yard few years ago... A lot of dollars with nothing really addressed! Do not recommend at all.
I will when all being cleaned and done and finished as well as the proper metal treatment have a fiberglass expert to do the finish work at the bottom of the hull...
I take also extreme careful advises from the sailing and local talents when under such surgery! Attached few photographs... I guess the stage in my boat is not as bad as yours... How ever when I purchased her 9 years ago it was somehow a similar vision...
It is a lot of hours, I mean a lot......... but will get there... The worth part is obviously underneath the head section.... I have designed an air nose handle to get to very tiny areas where you need on top of that extra small hands....and mirrors.... visibility and good insight being done with a small camera inches by inches...!
I will inform of the continuity of this gigantic project...
Best,
Vincent
Hi Vincent
I couldn't open your images .
If we do the project this year the idea is to cut out the entire frame in pieces to avoid cutting up the interior too much. We will have to cut the moulding of the head structure to gain access. We will then make up templates for a G10 "kit" to be fabricated by a contact of Lars. The g10 kit will be bonded into the hull to make the new frame. Sounds simple!
Patrick
Hi Vincent
I couldn't open your images .
If we do the project this year the idea is to cut out the entire frame in pieces to avoid cutting up the interior too much. We will have to cut the moulding of the head structure to gain access. We will then make up templates for a G10 "kit" to be fabricated by a contact of Lars. The g10 kit will be bonded into the hull to make the new frame. Sounds simple!
Patrick
Thank you - it looks like a great job. Do you have any photos of whet the step looked like before it was taken out and once removed. Did you actually take the whole frame out?
