I do both, infuse and bag wet lay up parts.
If the customer doesn’t mind the flattened look the carbon reveals when infused, I infuse .
If they want it to look like those Asian hoods I PER gelcoat then do a wet lay up with epoxy usually 60-90 min pot life.
I use Airtech as mentioned above for the supplies.
I get the Blue/Red release film with holes 1/2" on center.
I also use the thinnest Breather layer I can buy.
First weigh all the carbon or glass that will get wet with resin and add 10%-15%. That is how much resin I use period if I need more I did something wrong. Sometimes it gets scary near the end of the layup.
This will get you very close to a 50/50 resin to glass ratio or better. The object is not to try and pull out all the extra resin you put into the part, it is to squeeze the layers of material together while taking out any slightly extra resin you may have put into the materials.
My technique is to apply the gelcoat and let it tack.
Apply the epoxy resin directly on top of the gelcoat then lay the carbon in the mold. Some people wet both the mold and the first layer of material.
The most important thing is to either rib roll, squeegy or with a gloved hand work the resin through the carbon. Try to get most of the air out this way. I use long pot life resin so I can play with this first layer until I believe the air to be out. It is never completly out at this point.
Then on a seperate table I put down some plastic sheeting and wet out the next layer of carbon and squeegy off the extra resin, then put it in the mold. I do this to all the following layers. Next goes the peel ply and or the release layer with holes next the breather next the bag. Since I’m in florida I pull 30" of vac. I then stick it in the oven and cure at 175-200F in the mold for 3-4 hours. The heat in combination with the attempt to get out the air from the first layer works great for me.
When the vacuum is applied you should see small dots all over the
breather layer soaking up the slightly extra resin. If the whole thing looks like you infused it your part will have air in it.
The only way air can escape is if it has somewhere to go and if the breather is completely saturated the air can’t move anywhere.
As mentioned above this will take practice which = $.
Remember I have never heard of any one winning the lottery after purchasing one ticket for the first time.
This is the way I do it and I have very good results.
Again this is only my technique which may or may not work for you, but it may get you thin of things from a different angle.
I make some Porsche Cup car hoods that weigh between 3-4 lbs (carbon skins with an overexpanded honeycomb core). They attach with 2 rear hinges and one front latch. They don’t need hood pins and they see speeds in excess of 180 mph.
I have one customer that has had the same hood for 3 years.
Resin Services is where I get the resin and surface coats for vac. bagged parts.
The 212 resin with the 302 hardener is the most awesome in mold clear I have ever used. It is crystal clear and flexes with the part and does not print through.
It may be more expensive than you are used to but then again cool things never seem to be cheap in price.
Hope I didn’t put the group to sleep, even more I hope this helps you.
