DNA Owners Club

DNA Owners => West Coast chat => Topic started by: Furrari on April 02, 2019, 10:59:03 AM

Title: From the composit shop.
Post by: Furrari 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.
Title: Re: From the composit shop.
Post by: Furrari 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.
Title: Re: From the composit shop.
Post by: Furrari 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. 
Title: Re: From the composit shop.
Post by: Furrari 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.
Title: Re: From the composit shop.
Post by: Furrari 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.
Title: Re: From the composit shop.
Post by: Furrari on April 20, 2019, 11:44:59 AM
Fan arrived and ducting made ( no pics, 'cos it’s not pretty).  I decided to wire the fan into the pump switch.  What I learnt from this is that unplugging the soldering iron does not isolate the pump.  That made me jump, but it’s not the first time I’ve joined myself to the mains.  Will I never learn.
I’ve checked the oil in the pump and there is no signs of burning, the oil is still clear and the oil mist doesn’t smell of burnt oil so I can only assume it’s oil vapour not not burnt oil.  If my fan arrangement doesn’t solve the mist problem I’ll have to build a catch tank to filter the exhausting oil mist.  Not a big job and won’t require me to work with mains electric so I’ll be safe.

Anyway the test piece looks very good now that I can hold a decent vacuum, but I’m still not 100% happy with it on the vertical face, but the horizontal surfaces are really impressive.  After the show at Chetwynd Park this weekend I’ll try putting a 45 degree bevel on the vertical face and re-skin it.  I’m optimistic that I can achieve the overall finish I’m looking for.  It’s a long slow job, and a steep learning curve, but with the warmer weather it should reduce curing times from 2-3 days down to 1.
Title: Re: From the composit shop.
Post by: Furrari on April 23, 2019, 12:03:28 PM
Well, did the carbon fibre test piece work over the entire weekend?  Not entirely.  On the West Coast there are two “ box sections” to stiffen the front panel.  It was one of these I was using to locate the test piece but it’s a bit tight to fit the test piece as it makes it difficult to close the bonnet and there is a witness mark on the underside of the bonnet inner skin so rather than risk any damage that idea needs revision.

I’ve spoken to Brian and he said I could reduce the height of the rib things or even remove them if I replace the strength in the front panel.

So that’s the next iteration of the job.  We’ll get there in the end and the test piece did look good in the sun.  With the warmer weather I’m hoping the CF will cure quick enough.
Title: Re: From the composit shop.
Post by: Furrari on April 26, 2019, 11:22:46 AM
These are the things I’m on about.

In the second pic you may be able to see there was a bond width of about an inch (that’s 25mm in the colonies and other foreign parts).  I’ll pack round this area with baby poo and let it set before I cut the other side away so not to weaken the front.  The rubber bonnet/engine bay seal has been removed to save it getting damaged.  It just slides back onto the flange at the back of the flat area.  It’s already been off several times to get the ABS panel to fit.
Title: Re: From the composit shop.
Post by: Furrari on May 02, 2019, 12:20:10 PM
Well that’s the two rib/box members off.  The FG is very thick and solid, it’s taken two multitool blades to do it and it’s made the front panel under the bonnet look a right mess.  Not worried as it will all be covered by the cf.  Well why isn’t the new CF panel in place.
I’m glad you asked that.
 Firstly with the ribs out of the way the centre section is too short so I’ve made a new one.
Secondly, some jobs just keep getting bigger.  Directly behind the FG front is a steel crossmember come radiator support which is held on by three bolts at end.  Looking at this it definitely needs CF'ing as well, but when the new CF panel is on you won’t be able to get at the bolts (you can’t get at two on each side anyway as they are under the FG front panel). With a couple of shows on consecutive weekends it will have to wait a bit, the cut panel will just get a bit of paint on for now.

That’s the way some jobs go, you start them and then you see other jobs that need doing first, but it will look good when it’s finished.
Title: Re: From the composit shop.
Post by: Furrari on May 14, 2019, 12:02:36 PM
That’s all three bits of the front panel bonded together ready for CF but that won’t be for a bit.  So that I only have to give the composite shop a good clean once I’ve moved on to the next bit.

It’s always been a feature/problem that the rear parcel shelf and the original boot lid fit together but the new, over boot lid (if that’s a proper description) and the rear quarter panels have a large gap round them because of the outside stying and the Merc interior are different.  So I’m going to have a go at making a rear parcel shelf that mates the Merc bit and the Furrari bit.  Trying to get it to work with the folding roof bit is beyond my skill level so this will be designed to drop in when the roof is down at shows.

As the other projects from the composite shop I will be posting it as I do it so you’ll see all the errors so if anybody has any ideas or comments jump in.

I hope there will be more pics for this project as there’s more to see ( and room for more errors.)
Title: Re: From the composit shop.
Post by: Furrari on May 14, 2019, 02:26:09 PM
This is what I’m on about.  The corner bits aren’t there because of problems with the hydraulics struggling to lift the weight of the original boot lid and the over boot lid.

Pic 1). The gap between the over boot lid and the rear parcel shelf.  At its narrowest it’s 24/25mm.

Pic 2). The shape of the corner where the overboot and the quarter panel meet.  This is taken looking to the rear of the car.How am I going to do this? Don’t know yet but I’ll shape the middle bit first and worry about the rest later.
Title: Re: From the composit shop.
Post by: Furrari on May 14, 2019, 08:04:40 PM
First job.  Make a card board template.  From this I’ve made a foam board template.  I did this because the foam board is 2mm thick, the same as the ABS I’m going to use.  It’s also more stable and accurate to use as the final template.

The ABS will follow the line of the gap between the trim and the roll bar and the joint will be covered in a rubber T shaped extrusion to neaten it up.  The back edge goes under the upper boot lid which traps it and will give this section its final shape.

One problem I’m having is that I used tyre black on the parcel shelf before the last show and now not even Gaffa tape will stick to it.

Just a pic of the template.
Title: Re: From the composit shop.
Post by: Furrari on May 15, 2019, 12:38:48 PM
I now used the foam board template to make a pair wooden formers.  I only had one piece of 12mm ply big enough so the second one is only about 2/3 the correct length but this won’t matter.
After cutting the wooden former I checked that the leading edge was the correct shape ( it was) I haven’t cut the back edge.
Title: Re: From the composit shop.
Post by: kalifornia on May 15, 2019, 01:20:10 PM
Hi Mick

I might be interested in one of those
Title: Re: From the composit shop.
Post by: Furrari on May 16, 2019, 07:54:56 PM
Kal.  I’d see the final result before you say you want one.  If I don't like it it will be in the bin.

Using the ply wood as a template I marked out on the ABS sheet where the rollbar/parcel shelf join is, then drew another line 50mm on the inside of that as a cut line which I then cut with a jig saw.  From this I cut towards the first, or template line about 1” to 1.5” apart. I should say that before I made these cuts I tried heat gun bending first.  This didn’t go well as I got a wrinkled shape.  I used the wooden templates to trap/clamp the ABS and used the heat gun to bend the “fingers” down at 90 degrees.  The 2” long fingers look a bit long but I can easily shorten them later.  Test fitted it and it does fit.  I used the foam board to cut the bit that goes under the boot lid.  If you leave it too long the ABS panel bows, so you just cut a bit more off.  You can also open the boot lid and mark it from the edge of the parcel shelf

Pic 1). The “fingers” bent down.

Pic 2). The panel dropped in place.

I don’t know what that white patch on the pics is across the panel, it’s not there “live.”
Title: Re: From the composit shop.
Post by: Furrari on May 17, 2019, 10:15:30 AM
The design modification.  In the original post on the parcel shelf I said the back of the insert would be leaf rubber and the front tee shaped.  These were determined by the traditional method of holding bits in place.  With the new panel in place you can see this won’t work.  As the new panel is 2mm thick it means that the front needs to be the leaf shape to allow for the miss match in height which tee won’t.  The back will now be tee shape.

That’s it for a couple of days as life and car shows get in the way.

Just a pic of the level change I’m on about.

Title: Re: From the composit shop.
Post by: Furrari on May 20, 2019, 05:20:56 PM
Great weekend.  First show with Burton Car Club.  A small show in Market Bosworth on the Battle Field Railway line.  Free entry, free Train ride and free tea and coffee throughout the day.  Good food at sensible prices.  Makes a change for paying for everything and food at silly prices.

The Furrari is now the car of the week on the club website.

I had the parcel shelf panel in place.  Not quite long enough so I’ve added some fingers at the at the rear to give a better fit.  Just some bits of ABS bonded on with ABS slurry, should finish this mod tomorrow.  Also learned that you can’t drive with the new panel in place with the roll bar up, it gets dragged out.

Talking of learning something new, I learned you can’t stroke the cat with abs slurry on your hands.
Title: Re: From the composit shop.
Post by: Furrari on May 21, 2019, 04:29:51 PM
Finished adding the fingers that hold the new parcel shelf in place.  Very solid in place with no movement but still easy to drop in place and remove.  Next job is making the “fins” that form the shape of the back of the new 'shelf where it meets the boot lid.  No pics of these yet but I hope to finish them before Ragley this weekend.  As each one is a slightly different shape it’s time consuming, thank goodness I bought myself a bench sander.
Title: Re: From the composit shop.
Post by: Furrari on May 23, 2019, 08:54:32 AM
Talking of bench sanders and learning something new every day.  Don’t put your glasses on the belt of your bench sander and then switch it on.  They went the full length of the garage and ended up half way down the drive under the car.  What a silly thing to do.
Title: Re: From the composit shop.
Post by: Furrari on May 25, 2019, 01:28:06 PM
Ideas are starting to come together now.  The fins are now fitted.  They are 2mm below the level of the boot lid and spaced them 5mm from the boot lid to suit the rubber strip. The top land is 24mm and the sloping face initially 45 degree with the corner between the top land and the sloping face rounded off.  They are spaced out at about 40mm ish where the outer boot lid is more or less flat changing to 25mm where the boot lid starts to rise.  The top land stays at 24mm but I’ve kept the curve where the bottom of the fins meets the new 'shelf.  I think if I maintain the 45 degree slope it will look to big and heavy and give me problems with the two outer sections.  I’ve also reduced the width by an inch a side to give me some land to work with on the outer parts.

I’ve closed the back of the fins off with .5mm ABS.  You can cut this with scissors.

I’ve filled the area of the fin chambers ( can’t think of a better description) with foam board to keep the amount of filler required down (weight and cost) to about 3mm of the final surface.

No pics at this stage as there’s not a lot to see but I will show it when it’s filled.
Title: Re: From the composit shop.
Post by: Furrari on June 04, 2019, 12:39:24 PM
After many discussions and design meetings my plans for the new parcel shelf have changed.  It will still be the same shape and made from CF.  Ferrari wouldn’t have a CF parcel shelf so the Furrari shouldn’t.  I’m still hoping to use the ABS shape as a pattern/buck to make the panel.  If I can’t get it off then it will stay as it is.  The plan now is to produce the panel and have them covered in the same finish as the existing shelf ( automotive vinyl).

Edit.   The other thing is that if the visible part is CF it that it has to be 100% perfect or it will show every flaw in the surface.

Finished filling and sanding and I’ve sealed the surface with packing tape.  Sealing the surface stops the epoxy from soaking into the texture of the filler and keying it all together mechanically.

The next bit is to figure out how to do the front edge.
Title: Re: From the composit shop.
Post by: Furrari on June 11, 2019, 06:01:10 PM
Actually spent a bit of time on the Furrari today 'cos the cricket was rained off.
When I started the parcel shelf panel I made the fingers that went between the original parcel shelf and the roll bar 50mm long, knowing they were too long but would be easy to shorten later.  Today I shortened them all to 30mm and rebent them to 90 degrees using the V block I made when I was an apprentice ( so it’s over 50 years old). I’ve checked they all follow on to the curve and tomorrow I can start to glue/weld them together to give a better, smoother curve, assuming there’s no cricket.  ( ABS slurry mixed ready).
Title: Re: From the composit shop.
Post by: Furrari on June 13, 2019, 06:51:15 PM
The only time I get any work done is when the cricket is rained off, and it was rained off today.   Over the last two days I’ve welded a 40mm x .5mm strip on the cut down fingers that will go down the back of the roll bar. 

Next job is to make a support frame using the original wooden shape and some 25mm x 40mm battens left over from when we renovated the roof.  This will allow the CF to go on the new 'shelf inside the vacuum bag without crushing the wooden former out of shape.

This job is taking a lot longer than I thought it would, but I suppose if you are bonding 25mm - 35mm sections with 20 minutes between steps to allow the slurry to dry it will.  And this is only the first of three sections, although it is by far the biggest.
Title: Re: From the composit shop.
Post by: Furrari on June 18, 2019, 04:57:56 PM
You may have seen my post “Bad News” about a small mishap the Furrari has had.  This is what’s left of the grill.  There is one long horizontal rib left and one vertical,  these should be enough to give me the correct curves to make a new grill.  The Horsey is OK but I’ll look for a better one and I have another Novitec badge and can print another mounting.

All this means that I can soon bore you all with the process of making a new grill.
Title: Re: From the composit shop.
Post by: kalifornia on June 27, 2019, 12:29:13 PM
Is the rest of the car OK ?
Title: Re: From the composit shop.
Post by: Furrari on June 27, 2019, 08:03:21 PM
Cal.  A few chips around the grill aperture but the main damage is that the front has been dislodged but there doesn’t seen to be any other damage other than a few chips.  Chase paints are fixing it at the end of the month but I won’t be driving it in the meantime as I scared of doing some real damage.

I ordered some ABS the day following.  The suppliers have just told me that it’s lost in transit and they’ve no stock and the size I need is a bit hard to get.

Not to worry, I can fix it.

Thanks for asking.
Title: Re: From the composit shop.
Post by: Furrari on June 27, 2019, 10:54:15 PM
We're not doing well with the replacement grill.  The sheet of ABS has got lost in transit and the supplier has no more big sheets in stock and won’t have for over a week.  I think I’ll start phoning round tomorrow.  I’m not a happy bunny.