My Lotus build

[Randy V]

Yes I'll take a mold off the front & rear sections. To make new ones that will be openable (tilt). Only the center (cockpit) section will remain from the original body.

Just curious since you seemed to be taking the tougher road and working with fiberglass to build a buck... Look at Scott's build thread where he is making massive modifications to an RCR SL-C... I believe he is using all foam and drywall plaster to build his buck..

http://www.gt40s.com/forum/slc-clubhouse/46162-scotts-build-thread.html

 

[Mike Surber]

Very interesting build. Very cool. It looks like what he has to work with has more flat surfaces that the foam can be more firmly attached to. With the Lotus most of the surfaces are round & hard to attach the foam to firmly. Mostly I use a spray adhesive for that & the foam isn't super stable. So once I get the contours where I want I go ahead & put a layer of mat on. That gives me a nice firm foundation to sand on. I'm going to have to look into that DW mud he uses though instead of Bondo. Sounds cheaper & easier to sand. The drying time for DW mud has always been a draw back in my book. I like to slap it on & sand it off quickly LOL

 

[Fran Hall RCR]

I have Chevron B16!moukds and a body InStock for sale
Email for more info if you're interested

 

[John]

How much for the body Fran.

cheers John

 

[Mike Surber]

Bought some of that fast setting dry wall mud. They have some that's supposed to set up in 5 min. That's almost as fast as bondo. If this rain will clear & give me some working time. I'll give it a try.

 

[Terry Oxandale]

Would that load the sandpaper much more quickly?

 

[Randy V]

If you use the mesh drywall sandpaper, it won't load up...
Once you arrive at your final shape, you may want to give the whole thing a skim coat of plastic body filler to give your buck a stronger and more consistent surface...

 

[Mike Surber]

Would that load the sandpaper much more quickly?

Sand paper's cheap LOL

 

[Mike Surber]

Will probably use a resin based primer for the final stages (wet sanding) before paint.

 

[Randy V]

You're going to paint your buck? Not saying that it's out of the question - but certainly not necessary...

 

[Mike Surber]

Well the buck needs to be perfectly smooth & just the way I want the surface. Before I take the mold from it. So painting it is about the best way to get that surface I know of. I can wet sand & polish it to a mirror finish. I suppose if I used an epoxy primer I might get away with it being sanded & polished. Any other suggestions are welcomed. This is just the way I've always done it (right, wrong or indifferent LOL) Not my first rodeo at fiberglass & mold making. But I may make more work for myself than is necessary.

 

[Jerry Jackson]

Mike if you want an excellent finish that will polish to a gloss easily use Furan resin as the coating. You can apply it by brush. It is watery to start with and increases it's viscosity during the pot life, it is a catalyzed system. Apply multiple coats which will be over approx 90 minutes. It 'wet and drys' very easily and will polish to an extremely high gloss quickly. Polish it with Meguiars mold polish and lambs wool mop. Use Mirror Glaze release wax. Furan is designed for the application you have.

 

[Mike Surber]

Furan is designed for the application you have.

Are you sure of that? I looked it up & it's for foundry use as a binder for sand casting. Thanks but think I'll stay with what I know & know where to get the materials.

 

[Mike Surber]

Well I guess todays work would be filed under "ya gotta do what ya gotta do" LOL I thought I had the rear fenders just about the way I wanted them. But after cutting the wheel arches yesterday. I became a bit concerned with the amount of clearance above the tires. So today I added a piece of 1 1/2" foam & raised the top of the fender & flared the outside a bit. Gave me a chance to try out the hot dry wall mud. Put some on this evening & even though it's only supposed to take 5 min. to set up. I'll wait till in the morning to sand it (sun was going down anyway.

 

[Chris Huck]

Mike re coatings prior to taking a mould, I used 2k paint on mine and then plenty of wax. This always has given me a good mould surface.
I have tried just using 2k primer, flatted and then polished up with a mop to a good finish but it never seems to release as nicely as it does with 2k paint finish.
I think your method of putting a layer of glass over is great, I used filler (Bondo) and my buck had a lot of wooden formers to keep the shape correct, depending on the weather being dry or damp, the wood would swell and then contract which caused some issues, but a layer of glass would have stopped this.

 

[Mike Surber]

Thanks Chris yes that's what I usually use is a 2k primer then the paint over that & wax the crap out of it LOL I'm not using much in the way of wood. Just the rear bulkhead (tail) where I want a very flat surface (slightly curved). So the factor of expansion & contraction of the wood from differences in humidity/temp. Won't be a factor, the foam is not affected that way. By the way how is/did your 917 (if I remember correctly) come out?

 

[Michel]

This is what composite professionals are using when doing plugs or mold repairs ;DURABUILT Surface coat

You can found those materials in UK :
Durabuild Surface Coatings GlassFibre, GRP, Epoxy Resins & Hardeners, Vacuum Bagging Materials and Laminating Resins

There are 2 sort of;
1/ first one is an "heavy primer "you sue it when surfaces are to be finished roughtly and makes a good "screen " to previous mods with bondo , etc
2/ second one is a finihing liquid you can spary like a paint coat in fine lies and then you can sand fron 400 wet grit to 1000 and polish it extremly glossy

then after 3 times laying wax and polich mirror ; you will neither have any sticking to the brandnew gelcoat mold

Problem of 2K paints is ; if you do not have ventilated all from the coat surface it's areal lotery ;
One day you unmold perfect :thumbsup:
Another day ( with no reason apparently !!) you unmold with all the painted coat sticked onto the new mold gelcoat !!!!!!!!!!!!!!!:thumbsdown:

This Durabuild coat is perhaps pricy but save hundred of hours worh when this is happenning !

 

[Terry Oxandale]

Duratec may be the same thing over here. I used it on the McLaren project. Can be applied very thick, sands very easily, and can be buffed for a smooth finish for buck use. Is catalyzed as well. It's a bit pricy, but was well worth it in regards to building fiberglass parts from scratch.

Terry

 

[Jack]

x2 on the Duratec. Really works well.

 

[Mike Surber]

Yes I've heard of it. Haven't used it before but will look into it I'm sure Chrystaliner (my FG supplier) will have it.