Carbon Mast/boom Project

[BobBill]

Doug, the Partall product has hazardous shipping restrictions.

Know why? Bad stuff?

Why not use plain old floor wax paste?

[Doug Lord]

Originally Posted by BobBill

Doug, the Partall product has hazardous shipping restrictions.

Know why? Bad stuff?

Why not use plain old floor wax paste?

---------------
I have no experience using floor type wax. Partall paste#2 and PVA are used in combination for really tough pulling jobs. One side benefit of using the two together is that the part will have no wax residue on it. Thats probably less of a problem for you except if you're going to bond another tube inside the one you make. Just go ahead and make a test-do a small section and see if you can pull it using the floor stuff.....

[BobBill]

Thank-you Doug. I will likely go with the paste wax, as I have a can from past, but am seriously considering your suggestion, to be safe...but concerned about the components being harmful, was all.

[BobBill]

Did some research, going to use the Partall, if it drys hard...like candle wax used by Cherub mast makers...so the release agent does not soak into the carbon matrix base layer...almost forgot about that...

I like idea of heating later to facilitate removal...so it appears DL's suggestion will pan out. Merci.

[bertho]

guys,
don't know if available in your place, but I use resin from europe (sicomin sr8500) low temp resin, you can mix hardener to work up to 8 hours, (4hours in tropical country) cure at low temp (40 or 60 deg centigrade what is really easy to reach , and good mechanical result ,(ps: I'm don't have nothing to sell , just share information), SP from UK have a similar resin but without same impregnation capacity . I do my mast in two half,(can see some pict on the blog below) is not high tech or best mechanical perfection for sure, but it's work and final cost is acceptable, anyway less compare to a custom aluminum mast ! not including the soft rigging material, after using this rigging, I will not do another way !
all the best
bertho
www.fusionschooner.blogspot.com

[BobBill]

Bertho, outstanding pics and history. Amazing, stuff. I am awstruck.

I made a separate thread...hope you do not mind...Boat Building Porn...

[BobBill]

Originally Posted by Doug Lord

===========
I'd suggest using Partall Paste #2 wax covered(sprayed) with PVA.
And the properties of most epoxies are greatly enhanced by post curing in an oven. You can just build a temporary box or whatever to raise the temp for curing. Find out what the ideal post curing temp is for your epoxy then see if you can match that in a temporary "oven"-before you start(!).

Doug, would I need to use Partall Paste 2 and PVA? Seems the same or overkill? I am not sure what PVA is or exactly how it differs from the Parall paste...

Thanks.

[gggGuest]

Originally Posted by BobBill

I have decided not to consider boom, at this point, just to keep it simple for me.

There's a lot to be said for building a boom as a first project since there's a lot more room for error. If it all goes pear shaped then there's less material in the skip, and if it comes out a bit stiff and heavy, well its a bit heavy and that's it. The golden rule for stainless steel fittings on carbon is "don't use any". You should be able to build a mast with no rivets other than for T terminals (which present few problems because they come with their own backing plate. Boom fittings should be by webbing straps. For a goosneck the mast part should be bonded on carbon with an s/s steel bolt though to hold the other part on.

[BobBill]

Yep. But, boom needed would require backing for fittings from mast, unless I stripped and replaced and so on.

No hardware for this project. Just replacing current metal mid and top sections of Force 5 mast, with carbon section, sans metal. Simple as could be, basically.

If I can do simple top section, boom may be in future.

Thanks for advice, we saved it.

[Doug Lord]

Originally Posted by BobBill

Doug, would I need to use Partall Paste 2 and PVA? Seems the same or overkill? I am not sure what PVA is or exactly how it differs from the Parall paste...

Thanks.

----------------------------
PVA is a liquid polyvinyl alcohol and you use it in combination with partall paste wax #2. Wax it once or twice and spray or pour the pva. On 5' models I would pour the stuff in a dust free atmosphere with a clean receptacle at the end of the mold so none got wasted. It produced an exceptional gloss.
If you spray don't spray heavily-try to mist it. Don't brush it.
The advantage of the PVA in combination with the wax is that it prevents the transfer of wax residue to the part you're laying up as well as aiding in part removal.
PS-after the PVA dries it is dissovlable with water.

[BobBill]

I get it...thanks.

[BobBill]

Well, have to report a bit of apparent luck.

GybeSet suggested (Dinghy Forum on Sailing Anarchy) looking at windsurfer masts. Seems that may do trick, if correct diameter, and if not, may be able to customize...and there is outlet not far from here having a sale...can save some time and mess to devote to making other stuff, like foils, and save $coots perhaps.

[BobBill]

I have now thought to build a boom...as I can virtually eliminate fasteners and form a simple outhaul rig...but

When I went on the Cherub site looking at the boom build on this link http://www.uk-cherub.org/doku.php/te...etting_started

it appears the build used some 7 layers of carbon...and estimated weight of 1800 grams carbon, without epoxy.

Is that heavy? Seems a lot to me, if end product about 7 pounds or 3k to 3500 grams???