Need advice on infusion/vacuum line arrangement

I have a gap in my moulding knowledge where infusion is concerned.I'm quite happy to discuss wet laminating or prepreg but there is more certainty with those processes.The idea of using a small part for a learning tool is obviously the way to go and I think it would be a good starting point to find what level of vacuum is required and to put the rudder core in a bag with that amount of vacuum applied.If it doesn't collapse you have something to work with.I'm told that there is some very good software for determining the location of delivery tubes,but it is expensive.The alternative is to find somebody with enough practical experience to provide sound guidance but the problem with that is determining how many people are willing to give away valuable and hard won experience.

 

The common method is to do a couple of test infusions on a glass table with the exact laminate schedule you plan to use, or a couple of different laminate schedules to see what works best. Then see how far and fast the resin moves before the resin viscosity increases and slows down. This tells you how far apart the feed lines need to be, and on the first part add more of them and closer together. Flow media can be added or removed from specific areas as needed so it fills evenly.

 

Laukejas, As ondarvr said you need to do your own test samples with the infusion media and resin you plan to use to determine the resin distribution line spacing and spacing between resin feed lines along the distribution line. Resin viscosity and distribution media have most influence, then the bore size of the distribution lines and feed lines. And there is a big difference between distribution mesh media, but the fast ones will waste a lot of resin.
And there is nothing wrong with the Shade Cloth that Skip initially used.

Skip, if you had trouble removing it then you must not have used the perforated release film under the distribution mesh. You should be using this with any over the top distribution media.
You could have avoided the dry locked out spots by having peel ply only resin breaks between the vacuum lines and your infusion job, secondly segmenting the vacuum lines in very non symmetric jobs.
By using resin breaks you will never get any resin into your catchpot either, 300mm wide breaks are great but you will be surprised how effective even a 100mm wide is, stopping the distribution mesh short of the job also helps.

Laukejas, for a small part like your rudder if I was to do the infusion I would use 30% shade cloth (black stuff in Skips first infusion) it is cheap and wastes less resin, 8mm spiral distribution line at the leading edge with one 8mm resin feed line.
I would extend the peel ply by 300mm past the trailing edge and have the vacuum line there, same 8mm spiral.
I would stop the shade cloth 20mm from the trailing edge, ie short of the job.

Regards
Andrew

 

Andrew, Thanks for the advice, it finally got warm enough to do the last plank and the peel ply resin break did an excellent job in evening out distribution and leaving a dry catch pot.

Thanks again, Skip