Hi, i have notice that there’s a big difference on part which have been infused vs part done with wet layup method. i just did two part and after clear coating i can see that the part which was wet layed up looks much better that the infused one, the weave pattern on the infused one seems to have been squashed :(, has any one observed this or its because of my in experience since i’m new to the world of composites.
thanks.
You mean this look?
yep, i was just to upload pics showing the same details i was referring to :).
in terms of cosmetic part like mirrors … and other stuff on high end production cars like mercedes benz, lumbo, ferrari… can you see the same difference?
which one looks better, mybe i’m just worried over nothing 
Squashed fibers are telling to Your eyes: “quality!”
Wet lay up which gets baged looks squashed as well, prepreg also.
So only chineese low cost parts come “unsquashed”, I just wonder how they place tge fibers perfectly and have no bubbles? Usually those parts are made with 1 layer of carbon and a few layers of chopped strand mat…
That isn’t necessarily true. It also depends on the contraints of the project. If the constraint is fiber volume then a hand layup for the same volume of fiber can out perform a compacted piece of equal fiber volume. This is because the hand layup ends up thicker though heavier. The extra thickness increases the stiffness which can reduce the propensity of the structure to buckle under compression.
If the constraint is maximum strength for the least amount of weight then a properly compacted layup will perform better though an increase in fiber volume is required.
I’ve also tested infused and vacuum bagged laminates that were so porous that they performed rather poorly. Often vacuum bagged hand layups get too much resin leeched out of the layup due to the neglect of not using the correct perf-ply…or no perf-ply at all.
I use a lot of pressure assisted methods but they don’t determine the quality. A quality product is one that meets or exceeds the structural requirements and makes the customer happy. Some requirements require the use of compaction to increase the fiber volume fraction to meet a weight objective. Some requirements do not.
I think none compacted carbons look much better than squished ones. If the customer is wanting cosmetic bling, and doesn’t want the squished appearance, then the shop needs to alter their methods to meed the expectations.
The squashed carbon tells you that the part was either bagged or infused somehow. Unsquashed fibers are usually the product of an unbagged or overlayed parts.
I’ve noticed both on Lamborghinis and Ferraris. And believe me, I’m around them enough to know what I’m talking about ha.
Is there a difference? To us yes. To the customer, the difference is negligible.
Neither of which looks prove weather the product is poorly made or not. It only shows that the product was made differently.
I would not worry about it :). I don’t and I HATE imperfections. I’m not allowed to have a magnifine glass beceuase then I’ll never stop working on a product haha.
Well what do you think of this. I’ve noticed that if you have a thicker than thinner laminate, the fibers arent as squished.
For example. One of our products are those corvette door sills up above. 3 layers of carbon fiber, 1 layer of 18oz roving. The fibers look squished.
Another one of our products are Tesla Roadster door sills. 3 layers of carbon fiber, 1 layer of core matting, 1 layer of foam core. No squished fibers.
What do I think? I think that the fibers in the Corvette panel are squished and the ones in the Tesla Roadster are not squished. 
Your observations are a reality for the processes/techniques that you are using.
The squished fibers have a higher Vf than the fibers that are not squished. I would suspect that the core is distributing the pressure which prevents the localized pressure onto top of the fiber bundles. If a higher Vf were necessary you would have to use a different process. Again, if the customer is happy and the structural requirement are met, then squished or non-squished is not an issue. If you are going beyond the requirements and the cosmetic expectations then one could be wasting your time and money…that’s the fine balance of every company. It’s also often the difference between a profitable project and one that bankrupts the company. Projects can financially fail from not meeting the expectations or by exceeding them too far.
BTW, I’m not saying that squished fibers don’t make cosmetic oriented customers happy. Some notice some do not.
^^ Thank you point sent for a well written post!
I personall like both looks. Squished and non squished. Again, I see the two everywhere on all types of cars and projects. IMO both are acceptible. I personally like the squished look because it seems more proper to me. Thats just me.
thanks, no more sleepless nights over this coz i have been wondering if there’s something i’m not doing right :).