Lotus Elan

Cosworth YB Turbo Into Elan

PostPost by: nmauduit » Tue Jul 03, 2018 1:19 pm

stevebroad wrote:The deformation was over 5mm high and 50mm wide, so quite noticeable.

yes... my initial thought would have been that the vacuum bag did not have enough slack around the reinforcements and it is the plastic (when pulled by vacuum) rather than the vacuum directly that could cause distortions. Not as obvious as it seems indeed, and I will probably keep contemplating for a while rather than jumping in.
S4SE 36/8198
User avatar
nmauduit
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1353
Joined: 02 Sep 2013
Location: France

PostPost by: stevebroad » Tue Jul 03, 2018 1:27 pm

nmauduit wrote:
stevebroad wrote:The deformation was over 5mm high and 50mm wide, so quite noticeable.

yes... my initial thought would have been that the vacuum bag did not have enough slack around the reinforcements and it is the plastic (when pulled by vacuum) rather than the vacuum directly that could cause distortions. Not as obvious as it seems indeed, and I will probably keep contemplating for a while rather than jumping in.


The deformation is only under the reinforcement, the other three sections of the mould are fine with no issues. If I use the mould again I will repair the damage and remove the reinforcement.

As shown below, The bonnet is looking a little better after a lot of work.

bonnet-vent-gurney-280518-4.jpg and
stevebroad
Fourth Gear
Fourth Gear
 
Posts: 835
Joined: 08 Mar 2004
Location: Essex, England

PostPost by: pauljones » Tue Jul 03, 2018 1:33 pm

And Steve is a perfectionist too.

Its looking great to my untrained eyes Steve. Nice work

Paul
Kick the tyres and light them fires...!!!!!!!
pauljones
Fourth Gear
Fourth Gear
 
Posts: 968
Joined: 09 Feb 2008
Location: Gosport sur la mer,South hants

PostPost by: stevebroad » Wed Jul 04, 2018 9:31 am

pauljones wrote:And Steve is a perfectionist too.

Its looking great to my untrained eyes Steve. Nice work

Paul


Thanks, Paul

A failed perfectionist more like it. My stuff looks good from a distance :-)
stevebroad
Fourth Gear
Fourth Gear
 
Posts: 835
Joined: 08 Mar 2004
Location: Essex, England

PostPost by: Chancer » Wed Jul 04, 2018 10:05 am

Is it not simply that the reinforcement was foam (hope that right as I cant see the posting from this window) which would compress in the vacuum and that there was initially an air gap between the laid up material and the mould or the process off pulling the vacuum pulled between the material and the mould, thus the reinforcement would be compressed from both sides?

If the hypothesis is correct then using solid reinforcement would prevent it.

This is no more than completely uninformed idle speculation from someone who has never moulded anything and is in awe of your achievements!
Chancer
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1391
Joined: 20 Mar 2012
Location: Northern France/ Sussex UK

PostPost by: stevebroad » Wed Jul 04, 2018 10:12 am

Chancer wrote:Is it not simply that the reinforcement was foam (hope that right as I cant see the posting from this window) which would compress in the vacuum and that there was initially an air gap between the laid up material and the mould or the process off pulling the vacuum pulled between the material and the mould, thus the reinforcement would be compressed from both sides?

If the hypothesis is correct then using solid reinforcement would prevent it.

This is no more than completely uninformed idle speculation from someone who has never moulded anything and is in awe of your achievements!



When I say foam, I mean this stuff :-)

https://www.ecfibreglasssupplies.co.uk/ ... l-foam-5mm
stevebroad
Fourth Gear
Fourth Gear
 
Posts: 835
Joined: 08 Mar 2004
Location: Essex, England

PostPost by: nmauduit » Wed Jul 04, 2018 12:52 pm

Chancer wrote:Is it not simply that the reinforcement was foam (hope that right as I cant see the posting from this window) which would compress in the vacuum and that there was initially an air gap between the laid up material and the mould or the process off pulling the vacuum pulled between the material and the mould, thus the reinforcement would be compressed from both sides?

If the hypothesis is correct then using solid reinforcement would prevent it.


good observation, it could just be that the strong foam gradually compressed before full curing, then sprang back and the flex of the fiber gave to a slight bulge as pushing back from the now cured reinforcement...

so if not too tricky to prep an already cured part for adding on top of it (do one just need to scuff it like for regular fiberglass?), maybe an a way would be to add the reinforcement on already cured prepeg, possibly on a styrofoam kind shape (inside a plastic wrap) that could be disolved out with acetone after full curing?
S4SE 36/8198
User avatar
nmauduit
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1353
Joined: 02 Sep 2013
Location: France

PostPost by: stevebroad » Wed Jul 04, 2018 1:52 pm

Foam is designed to be under vacuum and have used it many times without a problem. The reason the first panel failed is because I lost vacuum and the heat caused the material to curl and separate.

With a decent vacuum the second attempt worked fine so my method is sound :-)
stevebroad
Fourth Gear
Fourth Gear
 
Posts: 835
Joined: 08 Mar 2004
Location: Essex, England

PostPost by: nmauduit » Thu Jul 05, 2018 9:12 am

stevebroad wrote:Foam is designed to be under vacuum and have used it many times without a problem. The reason the first panel failed is because I lost vacuum and the heat caused the material to curl and separate.

With a decent vacuum the second attempt worked fine so my method is sound :-)

ok thx, I like to understand the process, just in case.... ;)
S4SE 36/8198
User avatar
nmauduit
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1353
Joined: 02 Sep 2013
Location: France

PostPost by: stevebroad » Thu Jul 05, 2018 10:48 am

nmauduit wrote:
stevebroad wrote:Foam is designed to be under vacuum and have used it many times without a problem. The reason the first panel failed is because I lost vacuum and the heat caused the material to curl and separate.

With a decent vacuum the second attempt worked fine so my method is sound :-)

ok thx, I like to understand the process, just in case.... ;)


No problem. It's all relatively new to me so I am still on the learning curve :-)
stevebroad
Fourth Gear
Fourth Gear
 
Posts: 835
Joined: 08 Mar 2004
Location: Essex, England

PostPost by: pauljones » Thu Jul 05, 2018 11:00 am

Steve.

You clearly have a very good grasp despite you still learning. May i suggest if your after new info on carbon mouldings to look into the ultra high performance yacht industry and the methods/techniques they employ.

Something like the new Fast 40s etc. These are incredibly light, super strong and fast. Im glad i dont pay the bills.

Still amazing work.
(Im stuck on engine mounts still)
Kick the tyres and light them fires...!!!!!!!
pauljones
Fourth Gear
Fourth Gear
 
Posts: 968
Joined: 09 Feb 2008
Location: Gosport sur la mer,South hants

PostPost by: stevebroad » Thu Jul 05, 2018 11:12 am

pauljones wrote:Steve.

You clearly have a very good grasp despite you still learning. May i suggest if your after new info on carbon mouldings to look into the ultra high performance yacht industry and the methods/techniques they employ.

Something like the new Fast 40s etc. These are incredibly light, super strong and fast. Im glad i dont pay the bills.

Still amazing work.
(Im stuck on engine mounts still)


Way beyond my skill set and pocket depth :-)

What do you mean by you being stuck on engine mounts?
stevebroad
Fourth Gear
Fourth Gear
 
Posts: 835
Joined: 08 Mar 2004
Location: Essex, England

PostPost by: pauljones » Thu Jul 05, 2018 11:28 am

Steve,

Not wanting to hijack your thread but its sailing season so i spend alot of time on The water yacht racing. So ive not managed to sort out my zetec mounts yet.
Twincams on the bench. I do miss driving the plus 2.

Paul
Kick the tyres and light them fires...!!!!!!!
pauljones
Fourth Gear
Fourth Gear
 
Posts: 968
Joined: 09 Feb 2008
Location: Gosport sur la mer,South hants

PostPost by: stevebroad » Thu Jul 05, 2018 1:47 pm

pauljones wrote:Steve,

Not wanting to hijack your thread but its sailing season so i spend alot of time on The water yacht racing. So ive not managed to sort out my zetec mounts yet.
Twincams on the bench. I do miss driving the plus 2.

Paul


Doesn't bother me :-)

Do you have your own yacht?

What's wrong with the mounts?

Steve
stevebroad
Fourth Gear
Fourth Gear
 
Posts: 835
Joined: 08 Mar 2004
Location: Essex, England

PostPost by: pauljones » Thu Jul 05, 2018 2:40 pm

Steve.

I wish i had my own, familly cruiser is my Dads, floating caravan of 30ft.
Im lucky enougth to be able to still race on the Army and Navy yachts. I also still race on my old Corps yachts. Im trying to earn a living by offering racecraft training but theres alot of seriously good semi pro guys around here so its very hard to get into.

As for engine mounts, twink is out and on garage bench. I need to bolt in zetec and make mock mounts ready for welding.

Its being away that stops me progressing.
Kick the tyres and light them fires...!!!!!!!
pauljones
Fourth Gear
Fourth Gear
 
Posts: 968
Joined: 09 Feb 2008
Location: Gosport sur la mer,South hants
PreviousNext

Total Online:

Users browsing this forum: No registered users and 1 guest