DF 800 Traveller / Rear Hinge Corrosion

MJF · Post by **MJF** » Thu 15 Apr 10, 16:05

No doubt its common practice for many of you, but check the rear hinge where the traveller runs through the hull.

I was just about to launch my DF800 when I found extensive electrolytic corrosion.
The separating material had broken down and stainless steel, aluminum and salt water make ideal conditions for corrosion.

The traveller on the DF800 is structural so if it fails it would be a serious incident.

Oscar · Post by **Oscar** » Fri 16 Apr 10, 23:56

A picture would be helpful....

I you can put it on line somewhere, or you can e-mail it to the Admin, or me, and it can be posted.

oscar"at"noln.com

Post by **Bo Wetzel** » Mon 07 Jun 10, 9:41

Here is the picture:

Please click on the photo to see it enlarged!

Oscar · Post by **Oscar** » Mon 07 Jun 10, 18:09

Wow, that looks BAD. You sure that's electrolytic? Lot of those cracks look stress related. Good thing you caught it.

tpaliwoda · Post by **tpaliwoda** » Tue 08 Jun 10, 2:11

Well better to catch it now, then have a nasty experience on the water!
That is really bad! Let me know if you need a good marine metal fabricator.
You should really check all four well.

Paul · Post by **Paul** » Tue 08 Jun 10, 5:59

That really looks serious, will you will need to replace the whole traveller? Please post how you tackle the repair on the forum. I have now sailed my Df 800 6 times and have noticed that my traveller moves a bit - around 1/2 an inch side to side in winds over 15 knots. Is this amount of movement normal? I can see that the area where the traveller passes through the cockpit side has small stress cracks.

paul

MJF · Post by **MJF** » Tue 08 Jun 10, 22:05

The replacement job wasn't too bad.

I ordered a length of the traveller section from the UK importer which arrived within 5 days and was just under £200. it was a standard length 3m I think.

I took the old one out as a templater and took the pair to an precision engineering company to make the angled cuts and drill the holes.

Getting it in and out of the boat wasn't too bad.
1) Floats off
2) Both rear arms off
3) unbolt hinges
4) figure out which metal plate to remove
5) cut sealant inside & outside round traveller
6) unbolt hardware from traveller
7) drift (wooden block) and big hammer and tap out

pick up bearings from mainsheet traveller from inside boat

Reverse to fit new one.
Seal in with sicaflex 291

Prior to refit I made 2 spacers out of plastic to put between the Stanless hinges and alloy traveller and coated all touching faces in water proof grease.

The other side which showed no corrosion on the fron was badly pitted on the back. I think the problem was electrolytic corrosion to weaken and then stress to form the crack.

Hopefully it will be good for another 15 years now!

Paul - if there is any movement in the traveller I would take a serious look at it. The traveller on the DF800 is structural and takes the compression load when sailing. I'm not sure about other versions but would suggests its not good on any boat.

Paul · Post by **Paul** » Wed 09 Jun 10, 1:27

Nice repair job MJF, should be good as new. Couple of questions, the traveller appears to be fixed to the main hull by the 2 stainless supports bolted to the underside of the traveller and to the cockpit sides? Any side to side movement is resisted by the water stays -- am I right? I have not had a chance to crawl under the cockpit and have a good look, but will do so next time I'm at the boat. My stainless "hinges" and the alloy traveller where your problem occurred look good, no signs of cracking or corrosion, I was just concerned about that bit of movement in the traveller when sailing hard.

Paul

MJF · Post by **MJF** » Mon 14 Jun 10, 22:03

The stainless supports fit into the underside of the traveller in a channel. A M6 bolt tightens the stainless support to the traveller channel. There is a clearance hole in the beam itself.

I fitted them as the original, but cannot believe they stop lateral movement. they are only into fibreglass at the sides with washers. The hinges to which the traveller and arms are secured are 2 to 3 as thick and would take a much more significant load.

I believe the waterstays in concjunction with the mast tension take vast majority of the load when sailing.

If you have movement in the traveller beam I would check the bolts that run through the fibreglass and hold the hinge. You may be able to see cracks around the bolt heads. On mine they are coach bolts (rounded heads on the outside, square section under the head which locks into the fibreglass) If these were loose on the fibreglass ot may allow movement in the hinge and hence the traveller beam.

I would be keen to find out where the problem is, but do not think the stainless steel bars under the traveller are the problem or the solution.

Paul · Post by **Paul** » Tue 15 Jun 10, 0:21

thanks MJF, I will check the bolts as you suggested.

Cheers,

Paul

jonny · Post by **jonny** » Tue 15 Jun 10, 15:37

I also had corrosion around my bolts, and a big crack thru half the traveller just as the traveller goes inside the hull on my 800. I ordered a new traveller from Quorning in Denmark for 550 euro incl shipping to Sweden. The new traveller looked just like the old one except it was reinforced with an extra 3mm aluminium plate for the 3 bolts.

I did almost like MJF.
1. Support one float
2. Unbolt one rear hinge.
3. Cut sealant inside & outside round traveller.
4. Unbolt hardware from traveller
5. Drift (wooden block) and big hammer and tap out

/jonny