Author Topic: From the composit shop.  (Read 315 times)

Furrari

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From the composit shop.
« on: April 02, 2019, 10:59:03 AM »
I can't find my previous topic “ Fibreglass and stuff” so I’ll start a new topic which reflects more accurately the work it shows.  It’s a separate topic from “Furrari Build” as some of the work is a bit specific to composite work which not all our forum members are interested in.

Anybody with experience in composite (and anybody else) feel free to jump in and help me as most of this lot is made up as I go along on my journey in composite world.
« Last Edit: April 02, 2019, 08:24:17 PM by Furrari »
Not all problems can be solved with gaffer tape.  For those there is WD40.
Not even gaffer tape can fix stupid, but it can mask the sound.

If you can’t buy it or steal it you have to make it.

Furrari

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Re: From the composit shop.
« Reply #1 on: April 02, 2019, 11:59:18 AM »
Following on from “Furrari Build”  I’ve removed the headlight.  Given DNAs foresight the headlight unit is retained by one 14mm nut accessed from the engine bay and the wiring is all on superseal plugs so it’s out in seconds.  First job is to cover the plastic cover with a layer of masking tape so I don’t scratch it or get epoxy on it.

Should I do a wet lay up or vacuum bag?  Looking at it I realised that nether of these will work so I’m going to have to try something different and that I’ve never heard of being done, a hanging screen.

Second job is to cut a piece of CF bigger than you need and give it a LIGHT coat of adhesive.  This stops it fraying.  Give it 10 or 15 mins to flash off.  Then cut it to shape where it meets the cover.

On to the epoxy resin.  I gave the relevant surface a coat of black epoxy resin.  When this reached the beta stage ( tacky but doesn’t come off on your fingers) I put a layer of clear resin about 1/2” wide on the lip just below the start of the plastic cover and put the CF on it, and wetted this out.  Left it to cure.

When this reached the beta stage I removed the first couple of rows of masking tape so ithe resin doesn’t bond to the tape or the plastic cover.

That’s it for now, given the current ( in CF terms) low temperature I’ll give this a couple of days to fully cure (and give me more time to figure out how to do it).

As I’m making this up as I go wish me luck.  No pics as it’s only a pile of masking tape and a bit of CF sitting in a heap.
« Last Edit: April 02, 2019, 12:21:39 PM by Furrari »
Not all problems can be solved with gaffer tape.  For those there is WD40.
Not even gaffer tape can fix stupid, but it can mask the sound.

If you can’t buy it or steal it you have to make it.

Furrari

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Re: From the composit shop.
« Reply #2 on: April 02, 2019, 08:41:37 PM »
As the 1/2” strip of epoxy and CF had cured I moved on.  I dropped the headlight back in, poked the CF down past the edge of the surround area, marked and cut it.  The 1/2” land on the headlight is not vertical but at bit of angle so it slopes inwards and only hangs vertically after this.  I’ve used CAD/CAM (cardboard aided design and manufacturing) to make some, if they were metal you would call angle brackets.  I taped a couple of these to the surround and the now vertical face of the CF with about about an inch between them.  I wetted out in between the tape and the brackets and left it to cure.

When this epoxy had cured to the dry end of the beta stage I removed the brackets and tape so it doesn’t bond to the CF.  We'll see in the morning to see how it looks.  It’s not complete flat as the 1/2” land changes shape as it follows the shape of the headlight unit.

No pics 'cos all you can see is a headlight covered in masking tape. 
Not all problems can be solved with gaffer tape.  For those there is WD40.
Not even gaffer tape can fix stupid, but it can mask the sound.

If you can’t buy it or steal it you have to make it.

Furrari

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Re: From the composit shop.
« Reply #3 on: April 04, 2019, 12:47:32 PM »
Just a pic of the CF on the side of the headlight.

A bit I missed was masking up for about 200 yards around the headlight, positioning the skirt into place and give it a coat of adhesive so I could put masking tape on it and remove it without pulling threads of CF off.
« Last Edit: April 04, 2019, 12:50:35 PM by Furrari »
Not all problems can be solved with gaffer tape.  For those there is WD40.
Not even gaffer tape can fix stupid, but it can mask the sound.

If you can’t buy it or steal it you have to make it.

Furrari

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Re: From the composit shop.
« Reply #4 on: April 17, 2019, 12:53:02 PM »
More from the Composite Shop.

I’ve got one ore two ideas I want to put on the car, but I want to experiment first.  How to do these things are not on YouTube.

First the former.  I will be using ABS to give me the shape I want, but it’s only 2mm thick, so how do I join it together.  Tried super glue.  Total failure.  Tried acetone.  Almost total failure.  So I made up a slurry of scrap ABS and acetone and used that.  Almost worked and with a bit of triangle shape as reinforcement, success.  I think having it as a slurry it fills in any small voids from the sanding, giving more surface to bond.

Then to vacuum bagging.  Due to its shape it has to be vacuum bagged but following all the rules on how to do this has given me mixed results, and I’ve never been able to draw more than 60% vacuum which is not enough for this application.  Instead of using the approved bonding stuff (a bit like window seal stuff) I held the bagging down with the engineers go-to.  Gaffa tape.  Well what a difference.  90% vacuum and the bag pulled straight down, only a small leak from the vacuum pipe and I think I know how to fix this next time.

So it’s all sorted.  Err, no.  After running for about an hour the pump is to hot too touch and there’s smoke coming out of the exhaust port.  The CF forum shows this is not unusual with Chineseum pumps, but industrial units are between four and five times the price.
I’ve ordered a fan and I’ve got lots of foam board to I’ll make up some ducting to blow cold air onto the pump.

I’m reasonably happy with the product I got out but I think I can improve on it if I can run the pump longer.  The sample will be on test this weekend at Chetwind Park so we'll see how it performs before we go for the full scale bits.
Not all problems can be solved with gaffer tape.  For those there is WD40.
Not even gaffer tape can fix stupid, but it can mask the sound.

If you can’t buy it or steal it you have to make it.

 

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