I’m in the process of doing a small production run of cf hoods(10-20) and have been looking into my options as per what resin to use. Vinylester seems to be the best option for heat resistance but I read that it doesn’t properly wet out cf fabric. I did a few searches before posting this and didn’t seem to come up with a definitive answer on this subject. The plan is to infuse them either using (2)layers 5.7oz fabric, 1/8" dyvinimat core, (2)layers 5.7oz with no under structure. Or doing a similar layup using soric and having an under structure. Up until this point I’ve only been building small interior parts for my car and value any input you guys can provide on the subject. Thanks ahead for any info provided.
It won’t be as strong as epoxy, but whether that is an issue or not depends on what you need. The quality of the resin will play a big part too.
Plenty of bonnets have been made with vinyl ester resin.
I would like to use epoxy but I have no way of curing a part that large. Leaving me with a room temp cure epoxy as my only option which will soften up on the car. I was mainly concerned with the things that I’ve been reading about ve not fully saturating the fabric.
There might be some vinyl esters that won’t fully wet out the fabric, but it’s not all of them. Plenty of parts getting made with quality vinyl esters.
That’s what I wanted to hear. I was under the impression that it was all of them. Any good infusion ve resins that you recommend?
This might just be the VE you are looking for… http://www.compositescentral.com/showthread.php?t=9621
IF you use it please report back how you like the infusion.
I was wondering why you think room temp cure epoxies can’t handle the heat in a hood.
Several have a HDT of 200 degrees F or better.
Exactly. Not too mention it will post-cure in the heat as well. I actually use the heat from the sun to post-cure most of my bigger parts.
Print-through is the biggest issue. I haven’t seen any warping in my parts. Use an in-mould coating or post-spray a top coat and you should be fine. Use a high quality epoxy of course.
Any recommendation for such an epoxY? I have been searching for one with this type of temp resistance.
I’m in the same boat. After looking around I was left with the impression that room temp epoxies would soften when exposed to under hood temps. If that is not the case and I can be pointed in the direction of said epoxy I would use it instead of ve.
hi, i used to use epoxy based vinlyester to do my car parts befpre. i used infusion vinlyester resin, the parts are all good but the problems i had was the color of the resin. when i mixed with mekp it always turned dark brown. had a better results with poly in colorwise (clear) get a vinly resin and mix it and test if theres any color difference in the finished product. regards
PTM&W has at least 2 .
The PT2712 system has a peak Tg of 204 degrees F.
The data sheet is here: http://www.ptm-w.com/dynamicdata/dat…20bulletin.pdf
They also have PT5714 with a peak Tg of 302 degrees F.
The data sheet is here: http://www.ptm-w.com/dynamicdata/dat…20bulletin.pdf
Underhood temperatures will never be your problem. I’ve got carbon bonnets and fenders on a couple of 800rwhp full-time time attack cars here that in summer run in 35-40 degree days. The heat soak from the engine itself is negligible, I’ve never seen the bonnet get anything over 60 degrees C. I’ve even got engine covers and intake pipes here that only see about 90 degrees.
The issue you might have is if it sits in the sun for a bit and you’ve got a hot climate. In which case being black, the bonnet will absorb some heat. I have seen as high as ~110 degrees C.
The resin I used to make those bonnets and parts has a Tg of 93 degrees C, and I haven’t got any issues at all with distortion. I had some print through on them before I started using Duratec top coat, now I haven’t got any issues with them.
Thanks, the real world numbers are helpful!