Decided it was time to remove the old tramp and replace it with a new Slo version. Removed the front crossbar's two nuts per side with no issues whatsoever. When the crossbar came off, the cradles on both hulls were full of dirt? Cleaned up the cradles and everything looks good:
There appears to be no bedding material (silicone, silicone/polyurethane blend, caulk etc.) between the crossbar and the cradle. My experience with assemblies of this type is that there should be to stabilize the assembly and prevent working between the components. Comments?
A crazy thing I discovered while doing the tramp is that type of rivets used to attach the tramp rail on the port and starboard hulls is different. The starboard hull tramp rail is attached with aluminum rivets while the port hull tramp rail is attached with stainless steel (SS) rivets. Which type of rivets are OEM? Obviously, the SS rivets pull much harder than the aluminum rivets and are much stronger. I realized that a previous owner along the way may have re-installed one or both of the rails and inadvertently used a non OEM type of rivet. I was surprised that none of the rivets were installed with backing washers. Are washers OEM? Comments?
I noticed that the aluminum rivets on the starboard hull tramp rail were raised a bit. Is that common? Some of the Tramp rail rivets appear to have been installed without any type of sealant. I'm very concerned about leaks. Comments?
While poking around inside the hull, I couldn't help but notice how sloppy the lay up was. Truly a lot of dry cloth in places with excess resin (additional weight with no structural benefit) running in others.
I had a leak a while ago and found out if was at the tramp track rivets. I did a lazy repair for the occasion, just threw in some silicone and it worked fine. I was surprised that small openings on the upper part of the hulls would produce a rather noticeable leak. I'm not sure to need a more serious repair yet, but I'm interested to hear about yours. Good luck
My 84 has a lot of sloppy glass and resin inside that appears to be leftover from the original factory assembly. My tramp track rivets are the raised aluminum ones. I have placed a layer of silicone between the beams and hulls.
Thanks Andinista and Kevin.
Andinista wrote: I'm not sure to need a more serious repair yet, but I'm interested to hear about yours. Good luck
Right now, I'm just fighting to get the boat sailable as the season, for my style of cat sailing, (I don't do the 5mm wetsuit/drysuit thing) is over in about another 10-12 weeks. I probably won't do anything immediately, but was concerned that the raised rivets were pulling out and could fail on the water not to mention leak like a sieve as there is no sealant around them. I will eventually drill them all out and install new rivets with backer washers (where possible) and sealant.
wantanacra wrote: I have placed a layer of silicone between the beams and hulls.
Unless someone on here tells me absolutely not to, I'm going to bed the beam to hull with Boatlife Life Seal. It's a silicon/polyurethane blend that remains flexible and is removable.
Edited by leeboweffect on Aug 01, 2015 - 11:43 PM.
Aluminum rivets are OEM for the tramp. Don't do SS, too hard to pull, & you don't need the shear strength of SS.
The reason there are no backing washers is that there is no way to put them in place during fabrication.
If you have ports in your 5.0 hulls, they were added.
I have no ports in either the 5.7 or 5.0. Some of the 5.7 rivets pulled nearly out. I just drilled them,(the bottoms fall into the hull), dipped the new ones in marine silicone, & pulled them. Still good 3 years later, & we drive these boats hard.
That said, if I install ports, I would drill some of the loose rivets & use washers.
Don't worry about a few leaks, in fact it is beneficial not to have the hulls totally sealed. I purposefully leave a rivet or two in each hull unsealed, so as to allow pressure changes,(due to heating/cooling) to equalize.
I just tipped the 5.7 up a couple weeks ago, after 16 days sailing, & got two, maybe 3 quarts out of each hull.
E C Hilliard
Nacra 5.7
Bombardier Invitation
Edchris177 wrote: Aluminum rivets are OEM for the tramp.
Thanks Ed for confirming the aluminum rivets as OEM. That was my gut because the SS rivets pull so hard without backer washers that you could pull all the way through the glass. On the fifth photo in my original post (port hull with SS rivets) you can clearly see the glass has slightly shattered around the rivet.
My basket case came with 3/4 black plastic crossbar end caps. I'm missing one of the front caps that has a hole in the center for the trap bungee.
I don't find these new anywhere. Even a check on ebay brings up none used. Murrays offers an aluminum version which is heavier and VERY cost prohibitive.
http://www.murrays.com/56-3503.html
Does anyone know where I can get one of these (the black plastic version new or used) at a reasonable price?
Edited by leeboweffect on Aug 02, 2015 - 03:08 PM.
I posted how I made my own out of PVC pipe caps they come out prity good at a cost of about $10 for the parts.
If you need 1 made let me know and we can work something out.
http://www.thebeachcats.com/pictures?g2_itemId=108920
ohmsj
Thanks Jeff!!!
Original post of your N 5.2 End Caps project for reference:
http://www.thebeachcats.com/index.php?module=forums&func=viewtopic&topic=15066
Very impressive. Your caps look great. I think Ed is right.
Edchris177 wrote: Great solution Jeff.
If you are bored one rainy afternoon, set up your jig & turn out a dozen. There have always been people here looking for end caps.
I'm sure they will sell.
Please PM me with pricing and availability.
I'm tracking this project too. I haven't used any bedding or sealer on my beams, but it makes sense to do so. Those end caps are genius, I will be making a set soon myself. Besides being useful for sailing it would be nice to stop providing a warm shelter for bees and their nests. I have been to cheap to buy the dang things all these years.
dmgbear55, ohmsj and I are collaborating now for him to possibly produce some of the caps. Don't have pricing yet and I don't know if the caps are the same size for all the boats.
Thanks Ed for confirming the aluminum rivets as OEM. That was my gut because the SS rivets pull so hard without backer washers that you could pull all the way through the glass. On the fifth photo in my original post (port hull with SS rivets) you can clearly see the glass has slightly shattered around the rivet.
As stated above, aluminum rivets were standard on just about every part of these boats, except for some very high-load fittings on the mast. You are correct in saying SS rivets could rip through the hole in the fiberglass while being pulled. They are unsuitable and unnecessary in this application. Not to mention extra expense, and an extra 40-50 galvanic corrosion sites if you sail in saltwater. My tramp track was also raised off the deck because of old, soft, corroded, aluminum rivets. I replaced them all. I also had some minor shattering in the gelcoat around some of the holes. I have so many inspection ports on my hulls (ten!) that I could access the entire underside of the track, and when I replaced them all I used washers. Absolutely solid now. Also used lots of silicon, including a dab the the small hole in the rivet head after installation.
Thanks Tom. Over the winter I plan to drill out all the tramp track rivets and replace them with aluminum (with backing washers where possible as I do have an inspection port from which I can access some of them).
Looking around at aluminum rivets I find there are many options relative to body alloy (5xxx series for most), mandrel type, aluminum or steel, sheer and tensile strength etc.. Anyone have a good source for the more technical variety (the Home Depot/Lowes variety are the lowest strength I find)? Also, where an aluminum rivet is called for, like the Nacra 5.0 tramp track, has anyone ever tried the closed end version to prevent leaks through the mandrel barrel?
leeboweffect wrote: Looking around at aluminum rivets I find there are many options relative to body alloy (5xxx series for most), mandrel type, aluminum or steel, sheer and tensile strength etc.. Anyone have a good source for the more technical variety (the Home Depot/Lowes variety are the lowest strength I find)? Also, where an aluminum rivet is called for, like the Nacra 5.0 tramp track, has anyone ever tried the closed end version to prevent leaks through the mandrel barrel?
If you can get the closed ends, they obviously negate any leaks, BUT, the leaks are really a non issue. Just put a dab of marine silicone on each head. I leave one on each side unsealed, as a pressure release valve.
I would NOT use rivets with steel mandrels. If they are not decent SS, they will corrode. If you ever have to remove them it is a pain to drill out a steel mandrel, unless the rivet body is also steel. An AL body/steel mandrel will want to walk the drill bit.
I picked up AL rivets at West Marine, have no idea what alloy they are. Also buy bulk rivets from Bolts +, in Barrie. Again no idea what alloy, but they have held up for 5 years on the 5.7.
Honestly, I would just buy what is readily available, & cheap. If it only last 10 years instead of 30, so what?
E C Hilliard
Nacra 5.7
Bombardier Invitation
edchris177 wrote: I would NOT use rivets with steel mandrels. If they are not decent SS, they will corrode. If you ever have to remove them it is a pain to drill out a steel mandrel, unless the rivet body is also steel. An AL body/steel mandrel will want to walk the drill bit.
Thanks Ed. Agree totally with your comments on steel mandrels.
These folks seem to speak all things rivet:
http://www.stanleyengineeredfastening.com/brands/pop/rivets/types/closed-end-rivets
Lee
did you ever get end caps, if not let me know and we can work something out.
ohmsj
ohmsj wrote: Lee
did you ever get end caps, if not let me know and we can work something out.
Yes, "wantanacra" had an extra set that he was nice enough to send me, so I'm good for now, but thanks for asking.
did you ever get end caps,
If anyone else needs old style end caps, I've got a bag of 'em, some brand new.
E C Hilliard
Nacra 5.7
Bombardier Invitation
Here is a process that might lend well to manufacturing end caps from scratch. Obviously you would need an original in new or really good shape to cast the mold.
Somehow I think a good 3D printer might be better and cheaper. You could scan a single end-cap and make as many copies as needed, when needed.