Door Fabrication Technique/Method

How are the inner and outer skins of the doors typically laid up and joined on a replica? Are they simply an inner and outer skin bonded together after demould or a press mould bolted together pre-cure? Thanks.


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Brian Stewart
Supporter
Mine are simply inner and outer skins bonded together after demould.
 
Normaly there is a flange all around the edges of each side mold ; so after laminating each side with both molds "separated ", edges are carefully trimmed and molds are bolted one together with a compound made of resin and 'flocks" ( quality of this bonding stuff is very important to insure a durable bonding thru years !!!)
Skins when molded separatly are almost "flexible" and bonded with no "tooling " will give doors with random angle hardly matching to the spider angle
Almost laminating workshops have only one mold to laminate inside and then bolt together because it's a tuff work to laminate in one , then release and trim edge and insert in another mold with flanges to bond skins ; discrepency on molds or on locating skins will create "tension" when bonding
and a poor final result when curing
The quality of each kit bodywork supplier can be evaluate with the accuracy of this angle !!!
Specially if you watch at the edges ; very clever ones are able to create avery small return edge all around so when gelcoated and laminated carefully
this small 4 or 5 mm wall hide perfectly the bond in beetween the 2 skins, leaving only a very very small bead !!!If colored gelcoat is mixed to bonding stuff , you cannot even see this bead ...... so for non experimented eyes is hard to understand how doors have been assembled
Good providers have very well done door molds with thick flanges and hard external rinforces ( wood or tube frames) to be sure that, when bolting one to another the molds do not "flex" so that famous angle is always the same....
In order to manufacture such good tooling serious GRP suppliers have to set up a very nice assembled "plug" in wich doors have been carefully set to the spider on a mockup chassis with a mockup windscreen so the door plug is perfectly in place ; then the hard work starts in order to be able to do those external flanges and outside rinforces being sure to replicate the right plug angle

Because of the time involved into manufacturing "acurate"door molds ( of course not the well known on the market !!) some suppliers deliver doors unbonded leaving the home builder doing this extremly sensible step of body built !!!!! OUChhhhhhhh

Apologise for being so long !!!
Confucius was stating "one pic better than 100 000 words" !!!
I don't have any at the moment LOL
Hope this helps
 
I've seen moulds for the spider and front and rear clips, but never the doors. I have access to 3D CNC CAD/CAM in my work making large 3D architectural moulds for precast concrete so I intend to CNC each plug/mould in foam and then pull parts off that. The doors were a bit of a mystery to me though, so many thanks for the detailed techniques used ; )
First step is I need to buy a GT40 windscreen and take some 3D points off that to begin drawing the body up in CAD as without the screen, nothing can be progressed. It's going to be a long journey!
 
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