Books about composite boatuilding

slug zitski

Super Anarchist
7,097
1,467
worldwide
Vacuum infusion usually results in a heavier finished product than older hand lay-up methods. Why? because v/i completely fills any/every void with resin, where older techniques would have filled those with an ultra lite compound or left an air space. Kerfed core panels are a big source of gaps - as they are bent to the curves desired all the kerf slices open up to some degree. In hand layup these were filled with a very light fairing compound before the next layers of structural glass was added. Doesn't seem like much, but when J 105's went to direct weight measuring to achieve even weights, pre-scrimp (vacuum) hulls all needed about 250 lbs of added weights.
Yah

thermo formed foam is the way to go ..to many compromises with kerfs

even a home builder can thermo form foam
 

longy

Overlord of Anarchy
7,002
1,285
San Diego
Only if you use a suitable core material.
Even with bent foam, the butt joints between core panels will always have gaps. Those will fill with solid resin under vacuum infusion.
 

eliboat

Super Anarchist
2,325
709
Vacuum infusion usually results in a heavier finished product than older hand lay-up methods. Why? because v/i completely fills any/every void with resin, where older techniques would have filled those with an ultra lite compound or left an air space. Kerfed core panels are a big source of gaps - as they are bent to the curves desired all the kerf slices open up to some degree. In hand layup these were filled with a very light fairing compound before the next layers of structural glass was added. Doesn't seem like much, but when J 105's went to direct weight measuring to achieve even weights, pre-scrimp (vacuum) hulls all needed about 250 lbs of added weights.
If done right… not true. Also with an autoclave you can actually get better resin/fiber ratios than prepreg, albeit with an absurd amount of resin sacrificed.
 

longy

Overlord of Anarchy
7,002
1,285
San Diego
OK, how do you prevent infusion from filling all gaps? Short of a gap filling sequence? And why does an autoclave give better ratios? Since the pre-p method can give you any ratio desired? IIRC it's prime benefit is compaction of layers
 

eliboat

Super Anarchist
2,325
709
OK, how do you prevent infusion from filling all gaps? Short of a gap filling sequence? And why does an autoclave give better ratios? Since the pre-p method can give you any ratio desired? IIRC it's prime benefit is compaction of layers
First of all you’re not always going to use a kerfed core with infusion. The autoclave method I mentioned is not common at all, and I wasn’t suggesting that anyone take it seriously… merely pointing out that composites leave a lot of room for experimentation. At any rate, to answer your question the autoclave works in this case by pressing the infused resin back out of the laminate. In order for an autoclave to work on a laminate it needs to be under vacuum in the first place. So, in this particular case, the infusion is done under vacuum, and once complete, the part is then put into the chamber. At this point the pressure is dialed up to 50psi. When this is done the “excess” resin is then pressed out of the laminate into a pressure pot. This works using something like soric as a core, so obviously parts that would be suitable with that (ie not the hull of a big boat).

Consolidation of layers and good resin/fiber ratios are always the goal. While some claim they can get similar results not using a vacuum, the fact is that you really need to use a vacuum, insfusion or wet layup to get good results. Prepreg is by far the best option if you can afford it.
 

longy

Overlord of Anarchy
7,002
1,285
San Diego
Why go thru the work to squeeze the excess resin out when you can start with (pre-preg) the right amount of resin? Foam cores don't absorb any resin, so you need just enuff to get a full bond between the plies & the core. Easy to determine, then just use a higher resin loaded p/p as first layer
And all joints between core panels will get filled by infusion, and even with heat bending you'll have many butt joints across a hull mould
 

harryproa

Anarchist
924
160
As stated above, infusion in a mould is hard work and requires a lot of effort to optimise the opportunities to reduce the fitout labour and minimise the weight. It can be done without thermoforming or kerfs, see http://harryproa.com/?p=726 and scroll down to "Leeward hull".

Infusion of flat panels and flat panel moulds is a different ball game. It allows you to laminate the following in one operation:
– Both skins and the core
– Landings or slots for bulkheads, shelves, benches, steps, furniture, etc
– Self aligning edge joints, including for the two half hulls
– Perfectly fitting hatches and doors, plus their surrounds
– Rebates for windows, hatches, seats, doors, fittings, etc
– Accurately placed variations in foam thickness and density, including no foam in areas it is not required.
– Variations in laminate, including all local beefing up for high stress points
– Accurate, edge sealed holes for skin fittings, beams, masts and rudders
– Solids for attaching fittings
– Curves for seat backs, furniture edges, etc
– Sealing all exposed edges
– Plumbing, gas and electric cables, pipes, etc which can be concealed in the laminate or run along dedicated closed in channels.
– Variety of finishes such as formica, veneer, woven carbon, etc.

All this is done in 2 dimensions on a flat table, which is far easier than 3 dimensions inside a curved mould. The table does not need to be shiny, just fair. The infused component has finished edges and peel ply either side so there is no grinding or sanding prior to painting. Surfaces are inherently fair, so torture boarding is minimised.
The vac bag and peel ply are waste, but the savings in resin, time and effort are large.

The downside is you are limited in your hull shapes, but the longer/lower/narrower you make the boat, the less of a problem this is.

Check out Intelligent Infusion for more information.

Pironeiro, I'd be happy to discuss your requirements, which seem to be met by a Harryproa. Email me at [email protected] if you'd like to discuss possibilities.
 

pironiero

Anarchist
550
140
As stated above, infusion in a mould is hard work and requires a lot of effort to optimise the opportunities to reduce the fitout labour and minimise the weight. It can be done without thermoforming or kerfs, see http://harryproa.com/?p=726 and scroll down to "Leeward hull".

Infusion of flat panels and flat panel moulds is a different ball game. It allows you to laminate the following in one operation:
– Both skins and the core
– Landings or slots for bulkheads, shelves, benches, steps, furniture, etc
– Self aligning edge joints, including for the two half hulls
– Perfectly fitting hatches and doors, plus their surrounds
– Rebates for windows, hatches, seats, doors, fittings, etc
– Accurately placed variations in foam thickness and density, including no foam in areas it is not required.
– Variations in laminate, including all local beefing up for high stress points
– Accurate, edge sealed holes for skin fittings, beams, masts and rudders
– Solids for attaching fittings
– Curves for seat backs, furniture edges, etc
– Sealing all exposed edges
– Plumbing, gas and electric cables, pipes, etc which can be concealed in the laminate or run along dedicated closed in channels.
– Variety of finishes such as formica, veneer, woven carbon, etc.

All this is done in 2 dimensions on a flat table, which is far easier than 3 dimensions inside a curved mould. The table does not need to be shiny, just fair. The infused component has finished edges and peel ply either side so there is no grinding or sanding prior to painting. Surfaces are inherently fair, so torture boarding is minimised.
The vac bag and peel ply are waste, but the savings in resin, time and effort are large.

The downside is you are limited in your hull shapes, but the longer/lower/narrower you make the boat, the less of a problem this is.

Check out Intelligent Infusion for more information.

Pironeiro, I'd be happy to discuss your requirements, which seem to be met by a Harryproa. Email me at [email protected] if you'd like to discuss possibilities.
thank you!
 

slug zitski

Super Anarchist
7,097
1,467
worldwide
Why go thru the work to squeeze the excess resin out when you can start with (pre-preg) the right amount of resin? Foam cores don't absorb any resin, so you need just enuff to get a full bond between the plies & the core. Easy to determine, then just use a higher resin loaded p/p as first layer
And all joints between core panels will get filled by infusion, and even with heat bending you'll have many butt joints across a hull mould
Gee

Pre preg is for pro shops

Any thing that a singlehanded backyard boatbuilder makes will be less than optimum

Plenty of great less than optimum boats sailing around having fun
 

Steam Flyer

Sophisticated Yet Humble
45,462
10,222
Eastern NC
Just remember.... Each hour spent building is an hour less sailing..... And im a boatbuilder.
i know, but i think if you are interested in something-ivesting time in it dowsnt count as spent time.

The other thing is... there is only one way to make sure something (like, how your boat is built) is done correctly. We all know, you have to fucking do it yourself!

Having a series of small-ish, old/cheap racing boats that often broke because I sailed them hard, it's always been tempting to me to build a boat from scratch.

Then, having done a couple of small simple dinghies, the temptation to do a bigger fancier one has pretty much been extinguished.

There's no single RIGHT answer for everyone.
 

fcfc

Member
155
12
Why not look at this :
At one time, you could also get freely on gl site DNVGL-ST-0490 TP52 racing yachtsStandard

Beware that if you deal with class 40 , you will have to comply to class rules :

105. HULL CONSTRUCTION STANDARDS Any boat designed after the 1st of January 2010 must provide a letter to Class40 certifying that parts 5, 8 and 9 of ISO 12215 have been respected, as defined in OSR 3.03
You will also have material limitations:
401. HULL, DECK, INTERIOR STRUCTURE AND FITTINGS Materials forbidden in the construction of the hull, deck, the interior structure and fittings are:  Carbon fibre  Aramid fibre  Any fibre where the maximum tensile strength is in excess of 3800 Mpa  Sandwich cores: honeycomb cores. The use of resin pre-preg reinforcements in the construction of the hull, the deck, the interior structure and fittings is forbidden.
 

eliboat

Super Anarchist
2,325
709
Why go thru the work to squeeze the excess resin out when you can start with (pre-preg) the right amount of resin? Foam cores don't absorb any resin, so you need just enuff to get a full bond between the plies & the core. Easy to determine, then just use a higher resin loaded p/p as first layer
And all joints between core panels will get filled by infusion, and even with heat bending you'll have many butt joints across a hull mould
Because in some cases you can get better fiber/resin ratios at less cost than prepreg. This is for something like a surf ski or racing kayak. Again, I’m not suggesting this, merely pointing out some nuance when comes to infusion and composites in general.
 




Top