Harden Plastic Under the car

[stevenc152]

Hey,

Just curious, is this just to protect corrosion? I went up and over a kerb to get round some clown parked and abandoned a car, took a chunk of the plasic off under the car, Ive put plasic dip over it for now, looks to be a cover.

Plan putting some carbon fiber over it and sealing it up.

 

[Dr.Dash]

The undertray provides a number of benefits:
-Reduces the amount of water and debris getting into the engine bay, helping to protect the electrical systems, drive belts various pumps etc.
-Airflow management. Small drag reduction, aerodynamic front end lift reduction, and correct cooling (catalysts/DPFs can be quite sensitive to their operating environment).
-Can help reduce the fire risk from hot exhaust components and dry grass
-Noise reduction, a product of controlled under vehicle air flow.

Worth fixing IMO. And iirc cars fitted with one should have it in place for the MOT these days.

 

[stevenc152]

The undertray provides a number of benefits:
-Reduces the amount of water and debris getting into the engine bay, helping to protect the electrical systems, drive belts various pumps etc.
-Airflow management. Small drag reduction, aerodynamic front end lift reduction, and correct cooling (catalysts/DPFs can be quite sensitive to their operating environment).
-Can help reduce the fire risk from hot exhaust components and dry grass
-Noise reduction, a product of controlled under vehicle air flow.

Worth fixing IMO. And iirc cars fitted with one should have it in place for the MOT these days.

Thanks, would a patch job be sufficient? We have some carbon fiber and resen patches from working on a boat left over

 

[Dr.Dash]

Thanks, would a patch job be sufficient? We have some carbon fiber and resen patches from working on a boat left over

The airflow and physical movement of the car means they can vibrate if insufficiently rigid, and that will soon lead to a failure. A patch should be fine as long as it bonds well with the original material, you can always use some bracing and apply the patch over it if it's a large chunk missing.

 

[stevenc152]

The airflow and physical movement of the car means they can vibrate if insufficiently rigid, and that will soon lead to a failure. A patch should be fine as long as it bonds well with the original material, you can always use some bracing and apply the patch over it if it's a large chunk missing.

anything you can recomend

 

[dephead2004]

Tiger seal

 

[Dr.Dash]

anything you can recomend

I made an undertray for a Tiger Super 6 (like a Caterham) and used a number of aluminium battens and then layered the GF over that, it reduced the amount of GF needed hence keeping the weight down and was sufficiently rigid.

There's no reason why you can't use mechanical fixings too if you are concerned about bonding the GF/CF to the plastic undertray. Make your patch and once cured add some small flange head bolts (example here from ebay), backed up with washers and nyloc nuts.

You can improve the bond by good preparation. Thoroughly degrease everything after getting a good rough surface. You can even drill small holes, rough the plastic up with a dremel or even an old drill bit etc.

It there are any cracks in the plastic then a good way to stop them propogating is to find the very end of the crack and drill a 4 or 5mm hole there. It means that any force acts on a much larger area and so stops the crack developing further. HTH