Hi guys, Been looking at the resin infusion vids and it looks pretty straight forward. (famous last words) I want to make a 250mm diameter cylinder approx 1000mm length. However I need answers to a few questions please... How likely is it for the resin to reach the the other side and leave corners/edges dry? If its quite likely tips to prevent this? If this happens is the part still salvageable or ruined? Second question, This cylinder needs to be stiff (very very stiff) and upto 15mm thick, it does not matter if its thinner. What sort of layering would you use to achieve the above. Third question, I don't have a mandrill so intending to use a prepared sonotube cylinder, would release from this be difficult? Last question, cutting carbon fiber outside in the garden, would the dust just diffuse in the wind or linger in the garden for a couple of days? Looking forward to get started in this hobby, got loads of little projects planned... thanks, Jan

Hi Jan,

Answers to your questions as follows:

I want to make a 250mm diameter cylinder approx 1000mm length.
How likely is it for the resin to reach the the other side and leave corners/edges dry?

I don't think this will be a problem; it is an unusual shape for infusion and certainly makes the bagging process a little different but I don't think that resin infusing through the full shape should be a problem. I think I would set the tube vertically with a spiral all the way around the top edge, letting the resin flow down through the tube to the vacuum line at the bottom but it would probably work at any other orientation too.

If its quite likely tips to prevent this? If this happens is the part still salvageable or ruined?

It's pretty hard to recover a part in this situation, the only 'recovery' is to sort it as best you can at the time, usually by cycling resin through (into the catch-pot) as long as it takes until the last corners of the infusion are reached. This is very rarely necessary though and I'm sure it will go just fine.

This cylinder needs to be stiff (very very stiff) and upto 15mm thick, it does not matter if its thinner.
What sort of layering would you use to achieve the above.

Well, 15mm really would be an incredibly thick laminate although I suspect it doesn't need to be anywhere near this thick. To give you an idea of how you would achieve different laminate thicknesses, simply add up the thickness of the reinforcement that you plan to use, it really is that simple:

Please note these thicknesses relate to the following reinforcement types laminated under vacuum.
Open layup with the same fabrics would yield a thicker laminate. All thicknesses are approximate.

0.10mm  90g Carbon Fibre Cloth
0.25mm  200g Carbon Cloth
0.25mm  175g Aramid/Kevlar
0.35mm  200g Diolen
0.44mm  300g Aramid/Kevlar
0.60mm  450g Carbon Fibre Cloth
0.80mm  650g Carbon Fibre Cloth

This means that for 10.1mm you could use:
1 layer of 200g cloth as the innermost and outermost layer of fabric (0.5mm total) and then 12 layers of 350g (9.6mm total).

I don't have a mandrill so intending to use a prepared sonotube cylinder, would release from this be difficult?

Using the tube as a mandel or a mould? Either way, releasing will be difficult because without a 'taper' the part will be jammed pretty tightly on wither the inside or the outside of that tube. I think it's likely that you would need to cut the tube to get the part out of it or off it so maybe plan for this in advance by doing a nice job of putting a slit straight down the tube and then sealing it back up with hot melt glue or something similar so that when you're done you can prise the join apart and then contract (or expand) the tube.

Last question, cutting carbon fiber outside in the garden, would the dust just diffuse in the wind or linger in the garden for a couple of days?

This won't really pose any risk to your garden, it might look a bit sooty for a day or so but it will soon dissipate.



Matt Statham
Easy Composites / Carbon Mods - Technical Sales