There is a learning curve with infusion. I have not done it myself but have studied the process and always wanted to try it. It tends to be used in aerospace and race applications. I have seen a few large high end boats use the process. It is pretty neat to watch the resin spread on a large item like a boat hull. Controlling the flow of the resin is one of the things to master.
Hi Guys, as Wayne had mentioned, there IS a leaning curve:
The first model glider wing bagging I did was in 1973, so I have been at it for a while. I have (and still do) used this RI process many times on prototype, and production full sized (8M plus) military drones. In fact I am just designing a full sized light aircraft for a contract, so they'll be using it too later next year, or whenever this damn virus finally comes under control. So here's a couple of things to be aware of.
1. What ever method you use to control the inflow of resin, it can be difficult to control the thickness distribution all over the substrate or containment. Sometimes it may need a little "persuasion" with a soft (I use and old credit card) spatula tool to allow it to get into confined areas.
2. The actual viscosity of the made up resin has a very big effect on how the process works - or even if it works at all. Obviously the less the viscosity the easier it gets.
3. The ambient temperature in the process room must be carefully controlled to ensure that the pot life of the resin at low viscosity is sufficient to allow it to completely infuse all over the substate or containment. Too cold and the resin can be too thick. Too hot and it can turn thicker very quickly.
4. The resin infusion point has to be well thought out in order not to get gaps or bubbles where the resin may not flow properly.
5. To eliminate most of this its best to use an actual RI type resin specially formulated for that kind of use - problem is I'm not sure how available it is in small quantities and t aint cheap either.
Being honest, using this process for making model aircraft wings probably presents no actual advantages over the more normal mylar/breather/polythene bag method where the resin amount and distribution CAN be well controlled. The possibility for incompletely infused parts is high, and it can be a matter of multiple trial and error runs to get it right.
Note: The stuff from ACP - especially the small vacuum take off connectors is great but the vac pump assembly is way up there price wise. Better to buy a second hand vac pump ex dental or medical use and use the ACP vac switch which works very well- and the ACP connectors etc.
Another way if you want to get die straight mirror finish wings (or whatever finish you like) is to paint and/or gelcoat
formica shells that are taped together at the TE position - like an open book. Paint and lay up the semi-hard formica shells, put the foam wing assembly on to one side, and then close the formica "book" then bung the entire thing into the bag as per normal. You will get a knife like TE and a dead straight beautifully (the same as the shell) finished wing. The only downside is that the LE will need a little sanding - but I have used thick polythene strips here taped to the shell LE and that almost eliminated this drawback too.
Oddly I recently did a consulting contract for a local military sub contractor who wanted to use RI for making - can you believe it - replacement Humvee bonnets. (Hoods) Worked well after some messing about - as usual.
Have fun!
Doc.
