Could someone sell to me some Resinflow60?
I have had similar results (1mm thick dry areas on the inner surface on a 4mm carbon laminate).
I suppose it’s because I used the wrong mesh (resinflow 100).
I had to infuse with the slowest mesh.
This happened also in flat areas where no spray glue has been used.
how much do you need?
For the moment, just a few meters (10-20)for testing purposes.
Sure, but many people doing infusion do not have an absolute pressure guage…
As for the location, TX USA is a pretty flat state… every major city is below 1000ft… So i dare say it again, unless Mr Ro yale works up in the mountains, his guage pressure of 25in should be improved as a start.
so… since I’m living at 660m altitude can I not carry out my infusions with the same quality as someone at sealevel in their boat above the mariana trench?
This might help calculating backwards the absolute pressure http://www.engineeringtoolbox.com/air-altitude-pressure-d_462.html
Of course you can achieve the same quality… its just there is not as much pressure acting on the layup as at lower altitude. If you had a super accurate measuring device, you might be able to notice a small reduction in fibre volume fraction but thats about it - and it wouldnt be much.
The point is, even at your altitude, 25inches is not ideal. There is still significant air in the layup before your opening the lines. Any problems with strategy or execution, like resin encircling a dry spot etc will not fill 100% as there is still some volume of air in the dry spot. As the resin draws closer toward the center of the dry spot, the volume reduces and so thus the vacuum in the dry spot also reduces until its so low that the resin stops moving and the dry spot will not shrink further.
If on the other hand you have a perfect vacuum (or close to it) these dry spots will keep filling even tho the vacuum has been isolated. The resin will draw completely into the dry spot and fill it as the vacuum does not reduce with no air present - only the air in solution of the resin will hinder this movement as it expands and occupies some of the space. So typically you get some very small voids or bubbles rather than a huge dry spot that has no resin at all in it.
I always shoot for 100% vacuum - at your altitude i would be shooting for better than 27.5inches. If its not above this, dont mix the resin and abort the infusion. Keep looking for leaks or buy a better vacuum pump if it just isnt good enough to get that far with zero leaks…
THanks, I never thought about the air pockets like you just explained, but it makes sense. Same would potentially go for minor bridgning…
Thanks guys for all the help. I infused another mold tuesday with resin flow 60. We also used minimal spray adhesive. There was a perfect vacumn. Guess what? The mold totally infused and looks to be one of the best I’ve done. Just shows all the steps to infusion need to be followed. Infusion speed, adhesive quantity and vacumn integrity are very important. Again thanks!