West systems

[oncebitten]

Re: West systems

Extra resin means extra weight and that just doesn't do you any good. If you don't need the extra strength of the mat, I wouldn't use it. Your strength comes from the glass, not the resin. Use just enough resin to get a good bond between glass and substrait. That should be your best bet. Also beware of amine blush while you work.

Extra weight means lower speed, or more horsepower for the same speed. Just an opinion.

 

[crunch]

Re: West systems

Quote : Also I'd forget about the wood flour...just get more thixotropic powder (cabosil). For the strongest putties mix in some milled fibers. Quote:

Merton has milled fibers in 1/32 and 1/16... which to use?

I'm not concerned as to how the putty looks after it dries as I'm going to cover it with 2 to 4 layers of bi-axial anyway.

Merton also has 1/4" chopped strand. The putty will only be used to fill gaps and to radius the floor to the hull. The boats original floor was set back 1/4" from the hull and filled with resin ( I assume to prevent hard spots ) and filleted with foam... yuk !

As you can see from the sketch... there are no stringers or frames. The 3/4 white pine is just to attach the seats and to tie the keel to the hull via the floor (makes sense, it's all triangles when you look at it) The pine will be glassed to the keel with 4 layers of heavy bi-axil tape ( 17 oz. ), floor is glued with epoxy to the pine, then faired to the hull with 4 layers of bi-axial cloth ( 12 oz. ), then over laid with 1 layer across the floor and up the sides and transom 6", then another 2 layers up sides and transom tying into floor... this should give me a fairly stiff hull above the water line.

Any comments or suggestions welcome, I'm still feeling my way to a plan.

 

[crunch]

Re: West systems

Extra resin means extra weight and that just doesn't do you any good. If you don't need the extra strength of the mat, I wouldn't use it. Your strength comes from the glass, not the resin. Use just enough resin to get a good bond between glass and substrait. That should be your best bet. Also beware of amine blush while you work.

Extra weight means lower speed, or more horsepower for the same speed. Just an opinion.

amine blush? Seems I read somthing about that somewhere but I'm haveing a seniour moment here... what is "amine blush" ?

 

[sport15]

Re: West systems

Amine blush is the nasty waxy like gop that "floats" to the surface of a fast or medium setting epoxy. Some real slow cookers say thier stuff doesn't blush. Bushwha! I used slow cooking stuff on a skiff and sure enough, two weeks after cure I felt a slime on the surface, boy did it fisheye the paint! It can be gotten rid of with Dawn and warm water. That's why if you can do layer #2 while everything is still green you should. I've found that nothing sticks to that #@$%! blush.
Good source for glass etc. http://www.uscomposites.com

Dave

 

[oncebitten]

Re: West systems

Yes, Amine Blush can be washed or sanded. If you work wet on wet, you shouldn't have any problem with it. It looks like your keel box acts as a couple of stringers.

Consider running 1" x 1" balluster stock down either side of the keel box, or both stringers if that's open space in the middle of the keel box. I can't tell if that's a solid keel or two sides and two bottom panels like a mini-hull. Anyway, the 1x1 stock will give you a nice wide foot on which to glue down the sole. If it goes 1x1 /38 keel side/stringer- 1x1 you end up with a 2 3/8" wide surface on which to mount the sole. That way, you could probably eliminate the 3/4" pine boards bedded in foam.

As in this image... obviously ignore the bottom picture, that's my boat, not yours. Just the I-beam construction. Good and strong... like bull!

 

[Tail_Gunner]

Re: West systems

Yes, Amine Blush can be washed or sanded. If you work wet on wet, you shouldn't have any problem with it. It looks like your keel box acts as a couple of stringers.

Consider running 1" x 1" balluster stock down either side of the keel box, or both stringers if that's open space in the middle of the keel box. I can't tell if that's a solid keel or two sides and two bottom panels like a mini-hull. Anyway, the 1x1 stock will give you a nice wide foot on which to glue down the sole. If it goes 1x1 /38 keel side/stringer- 1x1 you end up with a 2 3/8" wide surface on which to mount the sole. That way, you could probably eliminate the 3/4" pine boards bedded in foam.

As in this image... obviously ignore the bottom picture, that's my boat, not yours. Just the I-beam construction. Good and strong... like bull!

Exactly how i layed my strigner's in, with one exception. i set the stringers in a urethane bed 3M 8609, same stuff used to seal or bed in your winshield on a car.........i just got caught up in all the hard spot stuff.. but there solid as rock now.

Damm wish i had taken a inventory eailer i could have save you some dough. Found a gallon of West systems left over and 2 gallon's of four lb foam lol it never cease's to amaze me.

 

[crunch]

Re: West systems

"Consider running 1" x 1" balluster stock down either side of the keel box, or both stringers if that's open space in the middle of the keel box. I can't tell if that's a solid keel or two sides and two bottom panels like a mini-hull. Anyway, the 1x1 stock will give you a nice wide foot on which to glue down the sole. If it goes 1x1 /38 keel side/stringer- 1x1 you end up with a 2 3/8" wide surface on which to mount the sole. That way, you could probably eliminate the 3/4" pine boards bedded in foam. "

It is a "mini-hull" and open space and I can't eliminate the 3/4 boards as I wouldn't have anything to bolt the seats down to except the 1/2 plywood.

The keel box is about 3/8 thick woven roving (no wood) glassed to the 3/4 planks. I cut the roving right at the bottom of the planks to remove the rotten sections, and will scab in Doug fir planks, wrap the existing sides of the keel box to the planks with 4 layers of 17 oz. bi-axil tape and epoxy, then glue the 1/2 5 ply to the planks with epoxy.

Still looking for some advice on milled fiber or chopped strand for the fillet putty... this has to be a structural joint at the hull/floor interface... I'm leaning towards chopped strand.

Thanx all for the advice, I'm stupid about this, but I'm learning 8)

 

[oncebitten]

Re: West systems

Exactly how i layed my strigner's in, with one exception. i set the stringers in a urethane bed 3M 8609, same stuff used to seal or bed in your winshield on a car.........i just got caught up in all the hard spot stuff.. but there solid as rock now.

I used small pieces of foam every foot or so to create a space under the stringer, then foced my fillet under the entire length of the stringer (or frame when doing them) and smoothed from both sides to get even distribution under each stringer. Then glassed.

Chopped strand/milled fiber. In my opinion, and I'm not a designer, just an amateur builder, if you're going to be running glass over the fillets anyway, I don't think it matters which thixsotropic you choose. I like wood flour because it's easy to control the consistency and work with wet-on-wet. Also, if you have to sand because you get called away after making a fillet, you're not sanding fiberglass, which makes me itch- have you ever noticed that. d I've used chopped strand and milled fiber, but didn't care for either. Again, just one guys opinion.

Also, the designer who's boats I like to build has planing models larger than 25' and I don't believe they call for anything other than woodflour for structural fillets or glues. I have maybe five or six sets of plans from 8' to 22' and they don't call for either milled or strand anywhere in the schedules on any of the boats for which I have plans.

 

[andy6374]

Re: West systems

custombycrunch-
Are you using epoxy exclusively?

Merton's sells a product called Hull and Deck putty. It's a mixture of milled fibers, poly resin, and some cabosil. All you have to do is add the MEKP. It is a ton easier/quicker than mixing yourself and not that much more expensive ~ $35 gallon. It's strong.

 

[crunch]

Re: West systems

Andy, I'm going to stick to the epoxy... uhhhh, let me rephrase that :%

 

[crunch]

Re: West systems

Ordered my list from Joe at Mertons today... what a nice guy!!

He took the time to go over my list and plans with me and instead of selling me more resin (as most salesman would) he assured me I would have enough to double coat both side of my floor, wet out all of the fabric, mix all of the fillers I'm buying, and have a bit left over.

The UPS shipping was a shock (around $50, but it's still cheaper than buying West Systems resin alone, below the internet cost, even with a 10% contractors discount from the local hardware store)... and the cost of the fabrics!!!! a 1/3 of the cost of West Systems.

(Probably should rename this thread Mertons 8)

 

[andy6374]

Re: West systems

Like I said Joe is the man, super knowledgeble guy and helpful. I order stuff so much that now when I call Joe says " Alright Andy what will be today?". And I always get it the next day, then again I only live one state away!