Best Material for Chainplates ?

[MJWEENZ]

Ice Man,
Look for posts from Maine Sail, he has several good articles including bedding hardware with Butyl.

MJ

[osirissail]

I used virtually the same technique as ICEMAN but opened up the deck area around the chainplate to 3/16" to 1/4" and made sure the FRG and chainplate were absolutely clean and chemically treated. Then filled the area with adhesive T5200. I managed to get some aluminum foil tape underneath the new hole area so could pour the sealant to make a flexible "plug". Then underneath the SS "collar" (rectangular) plates which are screwed into the deck edge I cut and installed 1/4" thick black rubber of medium softness. Screwing down the plates squeezed the rubber enough to force it against the chainplate sides. This has lasted over 10 years so far with no leaks.

[delmarrey]

Originally Posted by GordMay

Like 5200, 292 is Sika's polyurethane product. They're virtually interchangable.

Thanks Gord for the clarification, I haven't use Sikaflex and was not familiar w/the product class myself. So, it's unlikely I'd use it either.

But yeah, it's basically the same as 5200. 5200 does cure slightly harder and has a longer shelf life according to their spec sheets.

http://www.sikaindustry.com/tds-ipd-sikaflex292-us.pdf

http://multimedia.3m.com/mws/mediawe...6EVs6E666666--

[barnakiel]

How about the MS elastomer goos? Are they good to seal the chainplates?

barnie

[pressuredrop]

maybe i should start another thread for this but its sort of related so ill shoot here...

i am going to build some fiberglass chain plates, ideally i would like to bolt them on with countersunk heads and epoxy and then glass them on, glassing the heads completely, what you be the best material for the bolts? stainless no good since it wont be exposed to oxygen? i dont plan on glassing over the inside nuts, but these will be permanent...

bronze? or....

i know just glassing them on should/could be sufficient, but i will really sleep better in a blow if their bolted too...

Ben

[delmarrey]

Originally Posted by barnakiel

How about the MS elastomer goos? Are they good to seal the chainplates?

barnie

Don't know about that, but they do make good breast implants.

[delmarrey]

Originally Posted by pressuredrop

maybe i should start another thread for this but its sort of related so ill shoot here...

i am going to build some fiberglass chain plates, ideally i would like to bolt them on with countersunk heads and epoxy and then glass them on, glassing the heads completely, what you be the best material for the bolts? stainless no good since it wont be exposed to oxygen? i dont plan on glassing over the inside nuts, but these will be permanent...

bronze? or....

i know just glassing them on should/could be sufficient, but i will really sleep better in a blow if their bolted too...

Ben

If you use epoxy, which has a better bond then polyester, no water can get to the SS bolts. And why not use CF or kevlar to build the plates. FG is brittle and may break in a shock load situation.

[pressuredrop]

Originally Posted by delmarrey

If you use epoxy, which has a better bond then polyester, no water can get to the SS bolts. And why not use CF or kevlar to build the plates. FG is brittle and may break in a shock load situation.

Thanks del, i will look into those exotic fiber, maybe alternate fiberglass and kevlar laminate... if i do just fiberglass i plan on making them 1/2" thick, still think i would have to worry about shock loading?

[delmarrey]

I'm no expert on FG & composits but have worked with the stuff for 40 years. And to make a critical part like a chain plate from FG is a risk that I myself would not take. Even in CF or kevlar I would think it should be vacuum bagged with a metal insert in the eye.

I use to build dies for F-4 jet parts back in the early 80's and I know it's not an EZ process to get this stuff all together.

.

[GordMay]

Originally Posted by delmarrey

... I use to build dies for F-4 jet parts back in the early 80's ...

Are those F-4 parts dies, pictured?

[delmarrey]

Originally Posted by GordMay

Are those F-4 parts dies, pictured?

Those are the dies I built and a finished part (on the left) made of graphite composite w/alum. inserts. It was used for a bearing and gear mount to drive part of the landing gear. The die was all made of 17-4 SS. Unfortunately, the picture is old so the detail's are not so good.

[delmarrey]

A little off topic but here are some more pictures of the deatails. Is was a bit dark so I had to slow down the shutter speed and with my shaking hands, it's a bit blurry.

[pressuredrop]

hmmm well you making me really second guess my plan now, i guess i will build one and do some testing

i think i will plan on putting a stainless bushing...

i know GORD can answer this...

how thick does an epoxy fiberglass laminate 1708 biax+ heavy woven for its tensile strenght to equal that of 3/16" or even 1/4" stainless plate...

[barnakiel]

Just make sure those laminated chain plates have the glass fibres laid out the way you get max strength for any given amount of materials. Look up a North 3D sail and you will get my drift.

Maybe Spectra could be used with epoxy, but I do not know how Spectra goes with epoxy neither if there are any short or long term chemical interactions.

The other issue will be the bending - life cycles - will a laminated chain plate take as many cycles as SS or bronze, or will it crack?

b.

[pressuredrop]

in the case of the lowers and back stay, i plan on laminating them on a jig to get the (15 degree or so) angle for shrouds perfect so bending should be extremely minimal... i appreciate everyones input, but i really see this working