+x

 

AntoineLB - 12/27/2017 10:21:06 PM

Hello,
is it possible to make the carbon fiber car bonnet/hood (one of your projects) using the hand lay-up technique or if there is too many surface details on the car bonnet for the hand lay-up technique?

thank you and have a good day

+x

 

Matt (Staff) - 12/31/2017 9:58:36 AM

+x

 

AntoineLB - 12/27/2017 10:21:06 PM

Hello,
is it possible to make the carbon fiber car bonnet/hood (one of your projects) using the hand lay-up technique or if there is too many surface details on the car bonnet for the hand lay-up technique?

thank you and have a good day

Hi Antione,

Yes and no! You could certainly make a carbon fibre bonnet using the hand layup method, however it would not be possible for it to be as light weight as the resin infused version and it would be difficult for it to have such a good appearance (in terms of trapped air, weave alignment etc.) but with skill you could get both of these things quite close.

The problems you will face when trying to make a similar part using had layup are as follows:

1) Resin ratio - you're likely to use quite a lot more resin when you make a part using hand layup, at best you'll be 50/50 (resin to fibre) when an infused part would be 60/40.
2) Air voids / bridging - without a vacuum bag holding the carbon fibre down against the mould surface, you're likely to have problems with the carbon fibre lifting off the mould on the inside of tight corners or other details on the mould.
3) Air entrapment - when you do hand-layup, especially with epoxy resin, it's very difficult to not end up with tiny air bubbles in the resin which can be seen (if you look closely) affected the look of the finished part (if you're not painting it)
4) Weave distortion - not a major problem but you're likely to find that when you wet out the carbon fibre by hand using a brush, the fabric will be pushed around slightly which leads to unsightly distortion in the weave. Not s structural problem but not ideal if you're making cosmetic parts that will show the finished carbon fibre weave.

Therefore, it really depends what you want out of the finished part. If only the strongest, lightest part will do or if you need a showroom quality appearance then you're better off just biting the bullet and going for resin infusion. If it's not so important that the part is the lightest it can possibly be or if you're going to pain the part afterwards and so the cosmetic appearance is not critical then hand laminating a bonnet is a perfectly realistic option.

I hope this helps!

+x

 

AntoineLB - 1/2/2018 1:18:32 AM

Hello matt, another question for you, during part 2 of your car hood/bonnet you applied a polyester gelcoat with a spray gun. Is that really necessary or I can skip that part and still have a beautiful hood like the one you did?


thank you and have a good day

+x

 

Matt (Staff) - 12/31/2017 9:58:36 AM

+x

 

AntoineLB - 12/27/2017 10:21:06 PM

Hello,
is it possible to make the carbon fiber car bonnet/hood (one of your projects) using the hand lay-up technique or if there is too many surface details on the car bonnet for the hand lay-up technique?

thank you and have a good day

Hi Antione,

Yes and no! You could certainly make a carbon fibre bonnet using the hand layup method, however it would not be possible for it to be as light weight as the resin infused version and it would be difficult for it to have such a good appearance (in terms of trapped air, weave alignment etc.) but with skill you could get both of these things quite close.

The problems you will face when trying to make a similar part using had layup are as follows:

1) Resin ratio - you're likely to use quite a lot more resin when you make a part using hand layup, at best you'll be 50/50 (resin to fibre) when an infused part would be 60/40.
2) Air voids / bridging - without a vacuum bag holding the carbon fibre down against the mould surface, you're likely to have problems with the carbon fibre lifting off the mould on the inside of tight corners or other details on the mould.
3) Air entrapment - when you do hand-layup, especially with epoxy resin, it's very difficult to not end up with tiny air bubbles in the resin which can be seen (if you look closely) affected the look of the finished part (if you're not painting it)
4) Weave distortion - not a major problem but you're likely to find that when you wet out the carbon fibre by hand using a brush, the fabric will be pushed around slightly which leads to unsightly distortion in the weave. Not s structural problem but not ideal if you're making cosmetic parts that will show the finished carbon fibre weave.

Therefore, it really depends what you want out of the finished part. If only the strongest, lightest part will do or if you need a showroom quality appearance then you're better off just biting the bullet and going for resin infusion. If it's not so important that the part is the lightest it can possibly be or if you're going to pain the part afterwards and so the cosmetic appearance is not critical then hand laminating a bonnet is a perfectly realistic option.

I hope this helps!