Info thick layup 1in large 22ft long infusion

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#1

Hi

I need to know the best way to build up a spar. I will have to do a 60ply layup from a carbon tape 1inch large (by 22ft long), all in infusion. I will used a linear infusion method, so 1 full length of tubing injection resin to cross 1 inch of carbon layup,
with a resin break peelply of 2inch the other side. So question is :

1- To having a flat section to bond properly, do I put a caul plate on top of the
layup ?

2- Is using a 5/8inch large spiral tubing will be enought or an infusion mesh
will still be needed… ? I just need to travel 1 inch, but … better than a 3/8 tube…?

3- I don’t know if i do a layup over a flat surface : is the corner of it will bend, due to the bagging… ? Or then, the better might be to do the layup in a trench… mold type. But with a trench, is the tubing placing on top will be able to infuse the bottom of the layup…?

Thanks for tips.

#2

do a test first… Sounds like it shouldn’t be a problem but if you do a smallish section, like 2 ft long first, that should answer most of your questions.

I would think it’d wet out fine. But the test will answer that question definitivley and you’ll have proof in your hand as well as a piece to do some destructive testing on if necessary. Then you can measure for flatness, thickness, weight, etc.

Not sure what you mean about the corner? This is a completely flat spar? Or do you have a flange to bond to?

Do you have an illustration of the mold idea?

#3

Hi

Indeed i plan on a test, but I think may might have already done this. So here is the schematic of what i mean. As option 1 is a flat section. And the corner, being the side, might be deform due to the pressure…?

The option 2 might give a flat top, but i will not be able to monitor if it get infused properly. As to see the flow front…

Option3 could be in a mold as a L shape. But not sure if the bottom right will be infused right… ? No matter if resin input on top or at left.

It’s only a flat spar and i will do the flange later, not sure how by infusion…

#4

your caul plate idea would work, though it might be difficult to keep your stack and caul plate all where you want in a straight line. Not sure what your tolerance is for straightness and flatness but it might make sense to actually have “walls” on LE & TE sides of the SC. This is how wind blade SC are usually made. It would keep your SC straight as you want and you dont need a caul plate (but could also add this in if you did it right)

#5

Thank Hojo.
But if the fiber is put into a channel, how do it place the tubing. Having only a 1inch size tape, that might end up resin going to the output tube straight up to the catchpot… ?