ideas needed, Bump strip options??

martynwilley · 07-01-2012, 03:01 PM

hi,
im currently in the process of tidying up my ring21a and re-rigging ready for the race season ahead.

the bump strip on my 21a is a U section rubber fender stretched and bolted thru the 'sandwiched' decks.
at the beginning of last season this was brand new, at first i wanted no bolts thru so i tried just sticking it with sikaflex but this started to peel in a race and ended up flailing round whipping me an my nav, so after that i used s/s m5 panheads thru (even used small dia. penny washers top and bottom to try to clamp the rubber) this method has also failed and doesnt look 2 good.

what are my options? the lip around the boat has had holes drilled so many times that making nice regular even spaced fixings is almost impossible.

my only other thought was to grind the lip off alltogether and blend the 2 decks into eash other as it is laminated from the inside, would this weaken the structure of the boat and would it just crack where its blended everytime i take it out?

any ideas, methods or better type of fendering i could be doing/using?

thanks and happy new year all!!

Hydrostream · 07-01-2012, 06:15 PM

Yeah, blending them would be nice, but will crack if you dont put some glass on the outside too. Dont know how the top and bottom line up on your boat either so it may be a pain in the ass to get straight when your fairing the joint.
It will probably need a respray after the work too.

Other than that, I've seen large head rivets used from underneath to secure the bump strip. Put them every 6 inches or so, or where the flange is good.

Just thinking. When you put the bump strip on, did you stretch it on?
You need to cut it about 4 feet shorter than the length needed and stretch the shit out of it as it goes on. Putting it in a bucket of hot water helps. Then it only needs fixing at the back on both sides.

Big Dutch · 07-01-2012, 06:37 PM

S I K A F L E X

martynwilley · 07-01-2012, 06:37 PM

Yes I did stretch it when I bolted it,got about 5foot that I had to cut off. And on the cutting and blending, the 2 decks meet up nice on the back half of the boat but are about an inch out at the front such would make it difficult to blend or even attach a 'runner type flush bump strip. I think best option is to go for the origional u shaped rubber, bolt it on the back corner, contact adhisive strech it all way round an bolt it on the other corner?
Thanks for your input

martynwilley · 07-01-2012, 06:43 PM

M&G super discounted sikaflex!

think maybe the fact i didnt really prep the lip before sticking it didnt help, the sika pulled the paint off the lip rather than not sticking,

a decent amount of contact adhisive and a good strech is my best plan at the moment.

larby · 07-01-2012, 06:49 PM

I'd go for sikaflex every time over contact adhesive. If you want to be safe, just rivet the lower half of the rubber to the boat from underneath so they can't be seen. Edit, as Hydrostream said!

James

Hydrostream · 07-01-2012, 06:59 PM

Yeah, your kind of committed to a rubber section so, I'm with the lads 292 sika and stretch the shit out of it!

Hydrostream · 07-01-2012, 07:02 PM

By the way, I did a job recently that required a LOT of sikaflex 292 and couldnt get the amount I needed from sika, they were out of stock. They told me 252 was the exact same product without the same level of certification required for the marine stuff.
Long story short, it was half the price!

larby · 07-01-2012, 07:32 PM

Ooh, that's good to know!

Atec · 07-01-2012, 10:01 PM

i would be tempted to grind/sand the inside of the rubber. when they make moldings/castings etc there can be a release agent on the outside which also means adhesives dont stick as well + a good key always helps. sika over contact every time.