Lotus Europa Community
Lotus Europa Forums => Garage => Topic started by: buzzer on Sunday,May 19, 2013, 01:16:42 PM
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About to start the long path of restoring my europa special which I shall posting a blog on progress in the next few week. One of my first jobs is to repair the rear chassis mounts which have taken a beating and need rebuilding.
The question I have is should I use polyester resin or epoxy resin for the repair. I know epoxy is stronger but it's much more difficult to work into any profile shapes.
So any advice gratefully accepted
Picture attached with some of the original repairs which just pulled off!!
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On that repair you can use either. Epoxy with cloth may give you the strength you need in that area. Also you need to locate a new bobbin for the mount.
(http://www.lotuseuropa.org/gallery/albums/Zetec/Bobbins.jpg)
Not sure who sells them. Maybe RD Enterprises or Banks Europa.
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Buzzer,
I'm using polyester. I try and use glass mat when possible but sometimes I use cross (right angle) woven. I have several types of oz cloth on hand depending on the work.
I have the best results in small places using a Dremel for grinding and wire wheel. I buy the cheap bits off of Ebay.
But the biggest importance is cleaning. Get all the old paint and under coat off and for me I leave a rough surface for adhesion.
I also use Por-15 solvent for cleaning the surface are before start me work. It leaves no residue/film behind like lacquer thinner.
Once a can of resin has been opened and close several times it is best used up within 90 days.
Joe is spot on about the bobbin.
If you get into repair of the jacking point (which you really shouldn't jack there anyway) I did a write up on that here about five months ago. Using mat, poly and balsa wood. To make thing nice and smooth we are finishing with body filler adding a touch of resin in the mix.
mike
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Hi there,
Another vote for plain old polyester resin here, I can't see any massive benefits in making things more complex than they need to be in that area. From memory (always dangerous these days :) ) I think it's a plain aluminium bobbin in that location, just something to take the compressive stress of the bolt without damaging the fibreglass.
I'm not sure how I'd tackle that repair. I think on balance I'd build up the fibreglass first without a bobbin, taking the repairs along the horizontal section for 1-2" into good material and also up the vertical wall for the same distance using chopped strand mat. Once it was up to around 1/8" or more I'd line up and cut a hole for the bobbin, which you could align with a bolt while fixing it into place and you'd be certain it was flush with the chassis as well
As Mike says, cleanliness is the answer for a good bond, all the old paint needs to come off and the overlap area needs roughing up a touch. I use a wire brush on a drill and acetone for cleaning as it will soften old resin slightly and does make for a good joint.
I don't know about the US, but over here in the UK it's far cheaper to buy resin in 1 gallon tins from boat builders, etc, than small lots from the auto-shops. I generally use 2 types of glass matt, 300gms/sq M chopped strand matt for building up thickness and something called "surface tissue" or "veiling tissue". The latter is very thin glass, almost like a paper tissue and is used for making a neat surface over the repair. (I also use it for repairing gel coat cracks rather than body filler.)
I'm doing some body repairs on my Elan at the moment so I can take pictures of the materials in action if it's any help.
Brian
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Here are a couple of pages on how to repair a torn out bobbin.
(http://www.lotuseuropa.org/gallery/albums/Zetec/Bobbin_repair_1.jpg)
(http://www.lotuseuropa.org/gallery/albums/Zetec/Bobbin_repair_2.jpg)
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Good one Joe, I didn't know dem' pages were in the book.
One more thing I forgot to mention. Cure time. The resin gives off gasses and letting it cure before painting/coating is important.
We have two Elans sitting here that the last knuckleheads didn't wait............so there is bubbling under the paint in some spots.
Another thing that happens is smearing poly body filler over primer...........someone get me a gun. "that man needs killin'"
mike
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Cheers guys, some good advice there, I'll post some pic tomorrow as I have ended up cutting out the whole foot as it was completely shot, so going to build up the whole area. Thanks for the info on the bobbins, I have a copy of the manual and have looked it up on how to fit them. I have ordered some bobbins from sjsportscars, as I am missing both bobbin from the rear, well there was one that is just a lump of resin that just fell out.
I have already picked up some fibreglass and polyester resin on the net as well as acetone to clean up the body work and the importance of a clean base.
As I have cut out most of the mount I need to construct a mould for that area to reconstruct, which I plan to do some wood.cardboard and plasticine, then wax up to make sure it will release.
Dave
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Dave,
you can staple plastic sheeting to your form and do your layup. The finished product will just pop right off. Then file, sand and smooth.
Remember if you use mat with the longer fibers you can cut in certain lengths from the edges with scissors to form it better. Like cutting in on the material for shoulders on a suit coat. If you cut in V's then those can be filled with glass after your original setup has dried. Let us know......I dig pictures
mike
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Here's a few pics after I finished cutting out. I have strengthened up the inner wing and used a bit of carbon fibre matting to try it out which is the dark bit.
And then the pic of how I made up the mould with cardboard wood and plastercine.
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looks great!
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This is where I am up to now. The colours are the the pretty coloured plastercine i used. Going to lay in the bobbins next over the weekend and start on the other side. I should have some better pictures next week.
Dave
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It's looking very solid and neat. In fact it's probably stronger than the original was in that area, it's real flimsy on mine.
Brian
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Nice work Dave. For a guy that claimed he needed opinions...........looks like I should be asking you what I should be doing......
mike
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Mike, cheers, thanks for the compliment.. :)
Just had a morning chopping out some of the rubbish repairs that have been done previously, where it has been fibreglassed without removing the old paint. Been slowed down a bit as the missus has complained about the mess :( in the garage..
Dave