Advice for newbie

[Anonymous]

Hi,

I need some info on some items I want made.
The items are the 4 fins in the pic.

In the pic, they are made of fibreglass and are hollow. I want to duplicate them but using wood instead and with slight differences. I would be grateful for answers to my questions:

1. The whole thing is an undertray diffuser for a car. So using wood thats going to be painted, would it stand up to the 'road enviroment' ie. water, grit, dust, etc.?

2. If no.1 is OK, what type of wood is the most suitable?

3. Are there people who make items on request? If so, how do I go about finding them?

4. I would like to try and make them myself, but the thing I think is going to be difficult is the the tapering of each fin (like the cross section of a knife blade). What kind of tool is needed?

Thanks.

 

[Bean]

Hello eqr welcome to the forum. The thing that springs to mind is Ply Wood but for under a car it woukld need to be marine ply I guess. The fins could be made of ply again and tapered with a hand plane. As to finding someone to make one try a local joiners shop.

Bean

 

[Adam]

Hello and welcome to the forum.

Looking at the picture, I'd have to say IMO that wood would be the wrong material choice, and fibreglass would be my #1 recommendation.

Even outdoor ply, well painted would pretty soon start to suffer from ingress of water, due to nicks and chips from stones etc flying up.

Although fairly stable - it's a pretty harsh environment, heat from the engine, moisture, cold temperatures. I wouldn't be surprised if the individual layers started to break apart pretty quickly.

Maybe I'm being too negative? But I can't help thinking that in an inder car location, wood is the wrong choice of material.

No doubt some of the other members will be able to offer some alternative views!

Adam

 

[Anonymous]

Thanks for the welcome guys.

Looking at the picture, I'd have to say IMO that wood would be the wrong material choice, and fibreglass would be my #1 recommendation.

Even outdoor ply, well painted would pretty soon start to suffer from ingress of water, due to nicks and chips from stones etc flying up.

Although fairly stable - it's a pretty harsh environment, heat from the engine, moisture, cold temperatures. I wouldn't be surprised if the individual layers started to break apart pretty quickly.

Maybe I'm being too negative? But I can't help thinking that in an inder car location, wood is the wrong choice of material.
Adam

The fibreglass fins in the pic were ones I had made. I had wanted the fins more taper and sharply rounded off on the edges. But they couldn't make a mould to that shape. The pic was the best they could do. Thats why I wanted to make them with a different material. Also the fins are hollow - so can't work with them.

As to the location, they are mounted at the rear of the car, so no heat from the engine. Also stones chip won't be a problem as the fins are between the wheels and mounted far back.

 

[Anonymous]

hi eqr,

What are they for or what do they do?

Derek.

 

[Aragorn]

Hi EQR
My first impressions are to agree with Adam, but if these things aren't a concern then I can see no problem making up these parts in wood.
So suitability of the materials aside, the construction is quite simple.
A solid wood might be a better choice - something that's used to standing up to the outdoors like iroko or teak. If painted, the paint might not last long, but the wood will!
Construction would be a simple case of tapering some stock to the desired angle for the fin and then cutting out the shape on the bandsaw, then rounding/shaping the edges with a router.
I would estimate around 1 hours work for the 4 fins.
If you don't want to make them yourself, just look up a joiner or carpenter in your local papers or ask in a few hardware shops if they recommend anyone.
HTH

 

[Gill]

Would there not be merit in making a latex mould and casting a resin replacement? You could shape your orignals to the desired shape using a rasp before casting the latex mould.

Just a thought.

Gill

 

[beejay]

im a bit of a car nut myself and have had the tray off my little weekender several times and have seen the muck they pick up.
I imported mine from Japan last year and the underside was pristine but not anymore thanks to the winter weather and of course the SALT which will damage just about anything you decide to put on wood.
Id look at another material rather than wood as youd probanly be spending more time under the car than in it.
beejay

 

[Chris Knight]

Use wood and fibreglass. Make the fins in ply and coat in a couple of layers of fibreglass.

 

[Adam]

TI had wanted the fins more taper and sharply rounded off on the edges. But they couldn't make a mould to that shape.

You couldn't get the majority of it moulded with appropriate places to manually layer on fibreglass to get the shape you want? I know it would take longer than making it in a single mould but you would be able to make some complex shapes.

Adam

 

[ProShop]

If it's just the fins you want to make, then IMHO wood could be used, probably in hardwood, and the best way to get the fins to the exact shape you want is to use a hand plane and a sander as you only want 3 of them and they don't look very big.
To give some protection you could use a 2 part hardenening laquer available from good automobile paint shops. I've used this paint before in a harsh environment and it coped well.

Or as Chris's excellent suggestion, when you've got the shape you want cover it with fibreglass, it's fairly easy to do (a moment of nostalgia coming over ) I used to make motorcycle racing seats this way. ( Oh gosh another moment coming ).

 

[samlarsen]

I'd cut them from solid plastic. A plastic supplier could avise which to use.

Assuming you're using this car on the road (?) the last thing you want to happen is for the wood to fatigue (fatigue strength for some timbers isnt great) and the whole assemby to fly off at speed killing a pedestrian outright (?).

I know someone who had her boyfriend killed by an exhaust, which detached from a car her was driving behind, after it flew thorough his windscreen at 70mph.

Sorry to saden the tone of this generally jolly forum!

Cheers

Sam

 

[aldel]

eqr

I think the fins would be fine in solid wood. May I suggest Ash. I believe the chassis of Morgan sports cars were made of ash and the frame for the Morris 1000 Traveller was of the same material. Use stainless screws to hold it together. Make a pattern from cardboard of the original and cut out the new ones with a jigsaw. Taper with a hand plane. you could paint them with an epoxy paint for toughness.

aldel

 

[jasonB]

I'd make then from polyurethane foam which can be easily worked with handtools and smoothed with glasspaper, then apply a couple of layers of glassfibre. Light weight and waterproof.

http://www.cfsnet.co.uk/acatalog/CFS_Ca ... LS_14.html

Jason

 

[Losos]

egr - FWIW I'd do it in wood with a GRP skin, you'll be able to get the shape you want & the GRP will add considerable strength without much weight. It will take longer but it is a labour of love that car I guess. Use the woods recommended above.