Infusion Q&A

It seems a relatively new product.

What I do not like, however, is their last lines: "we have reports on its behaviour in laminates, but we cannot let you know the contents."

I really would like to see a report, by an independant lab.

 

Hi Herman, the full sentence sounds better: "Due to the sensitive nature of working with Military contractors, I cannot give their specific property results, but I can reaffirm, I have never had any physical property failures due to StayZ."

 

resin infusion

hello..
does anyone here can give me advise about infusion?
if i have a vertical (2 meter height)panel.. it should be infused from upside to bottom or bottom to up?
many thanks

 

From the bottom upwards is more fool-proof. gravity has quite some influence on resin flow. Infusing upwards will show a more balanced and level resin front.

 

Yup, there a tendency of fabrics stack will dry out..
Thanks Herman. But hv u tried?

 

Yes. From bottom up gives a much more consistent laminate, less problems with race tracking, and less trouble. Of course with more complicated structures you cannot always help infusing parts from the top to the bottom, but in general I try to avoid that.

 

Hi,
What is the best, infused at full bar (30"hg) or lower than that. I'm in a middle of trial of infusing vertical 8'x4' panel.

 

Prepreg

Prepress generally requires an autoclave but progress has been made by companies such as acg which means much lower temperatures can be used and you can get away with just an oven. Prepreg also gives you a higher quality laminate as the manufacturer has got the glass to resin ratios sorted for you and there is no risk of dry spots that you might get with infusion along with controlling resin gel times. Need to be good tailor though and it is expensive

 

Male vs female molds.

Hi all
All the videos i have found have shown infusion with female molds. Is there a reason why female molds work better or just co-incidence?

Thanks
Mick

 

Male moulds or male structures are no problem either, but make sure these are airtight as well.

For instance, a strip planked foam boat outer laminate can be infused, but only if the foam structure is airtight. In practice this means that you will probably have to hand laminate an airtight laminate over the foam.

 

I would primarily say because the well finished (non Porous) female mould surface lends itself to Vacuum integrity more (which is critical) ,also the high fibre percentage of infused parts makes fairing more difficult and the principle is defeated by male moulds and fairing compounds IMO

 

Thanks Herman and Latman.

The reason I ask is that I have been watching a series of videos and reading a building blog by FRAM from the Netherlands and in there he infuses a hull (3 actually) using the corecell as the mold. Again its a female mold and it seemed to work really well. He sealed the corecell joints and seemed to have no issue pulling the vacuum. It seems that I could do this also, but in reverse...i.e. Male Mold.

And on a different question...moulding two halves of a hull as FRAM has done...sideways and joining down the centre line. That seems a bit odd to me. I'm sure the designer has sorted it all out but I thought that having the split right at the apex of the hull was a bit odd. Is this normal practice that people have seen??? Would it bot be better to have a hull "shoe" and build the boat up from that???

All learning questions, not saying anythign is wrong.

Regards
Mick

 

I supplied about everything to Henny (Fram). Making the hulls in a left and right halve, then joining them in the centre seems to be the "standard" in multihull construction. A bit odd, but not wrong. At least you save on mould stations.

Getting the foam airtight was quite a challenge, by the way. Takes a lot of time.

The exterior of the boat has also been done in the same way. About the difficulty of fairing later on (latman in previous post). I do not agree. First of all an infused laminate is quite consistent, so less fairing to do. Second, fairing is not about cutting through your fiberglass, but through fairing compound. Especially with these flimsy skins used on multihulls.

 

Thanks Henman.
Re the airtight I see he fills the joints with the putty mix after routing out. Thats fair enough and like you said a fair challenge to keep a vacuum.
Regarding the split mold. What is the detail of the joint down the middle. Glass tape inside and outside??? Is there a "bump" issue with the extral layers of laminate??? OR does it all go together with the full hull bagging?

I am a bit daunted with the full hull bagging....my boat will be 60 foot!!! A Lotta bag!!!

And again thanks for the input.

Regards
Mick

 

Just a load of (staggered) tabbing. Recess the foam and fairing is minimal.

Recessing the foam can also be done where glass overlaps (anywhere on the boat)