If you still got sanding marks from the orbital sander, you didn't work well with the lower grits.
I highly doubt that your mold would last any longer with a better finish. At least not with proper release agent, and at the number of parts you might do.
If the marks are not to deep, sanding them of the final part will be much easier, as they are positive on the final part.
If you really work your mold to that high standard, you should definitely try inmold coating. No need to pay the painter then. I usually use standard 2 component clear laquer, and add the first layer when it is still slightly tacky. So no spray adhesive for the first layer.
post curing is pretty straightforward if you got the right equipment. Follow the instructions of your resin. But leave the bag closed for the process, as this reduces print through. In polyester molds post curing can only done to a certain degree. Maybe you have to do the higher temperatures off the mold.

Yeah I guess..  I got a fairly gloss finish so I bet it will be all right after clearcoat.   But I realy like to get rid of all sanding traces from the orbital sander.. It is better to get the least amount of work to do for the painter to get a good end reault. I have yet to be supriced over how well a painters work is done.. I always seem to find something I need to fix or don´t like when they have done their job.  Also the mold will last a bit longer with a high gloss finish and a better release as you said..  Thank you for the info about the tack spray mabe I will use it in the corners.. I will see how easy I think the layup will work out.. Have you any experiance of it after post curing your parts in the mold?

This hole process for me is not just to get the roof done. It is also a way to learn about how all materials work and to get the resaults I want to my standards and to get the ability to choose what is good enough and what´s not and how to fix it.  If I learn the process of makeing parts I will be able to plan better and maybe sell some of the parts I am making.  When the roof is done I will try and make interior panels and wider front fenders.. One step at a time though..

If you are going to clear coat it afterwards, a bit of spray adhesive won't be a problem, as you should sand the surface of you part before painting. For the same reason, you should not waste your time, buffing your mold to the highest gloss. Just keep sure everything is flat. The glossier your mold, the easier the separation from the part, but a final sanding with 2000 and a light polish is already more than enough.

I started with the wet sanding of the mold surface. I started with dry 500 grit  and my orbit sander and continued with 800 wet, 1000 wet,  2000 wet and even 3000 wet.
I had a professional product of chemical rubbing that I used with a professional polishing machine. I got the gloss but it didnt remove very much of the scratches.. The polishing compound is rely old too..

I will order some more polishing stuff from easy composites and see if I get a better result.. Have to wait for it though..



I have a layup question..
The roof is  about 105 cm wide..  I will use a 125cm 200g twill wide fabric and cut it down for a surface layer, back it up with 100cm wide surplus 2/2 380 twill for 2 layers and a last layer of 200g twill also 100cm wide.  1160 grams total per square meter which will give me a thickness of about 1,2mm if I get it correctly 

I have to extend the backing materials with a 5 cm strip.. Do I lay it up edge to edge or is it better to have some over lap? If I do overlap, it will be slightly thicker where the overlap is and I am afraid that it will be some kind of print through or deformation there.. Especially when I will be doing post cure heat cycles  later. 



One more question about the layup..  I am having nightmares of having bridging in the corners.. I have fusion fix GP spray adhesive but I am afraid of visible defects..  I will have the finished part clear coated though.. Is it rely possible to clean everything of after post cure cycles and have it clear coated without visible traces?

I caught the flue so updates are slow..

I layed the roof mold to the roof plug and it was not that bad actualy..


Since it is bent a bit it is a bit short and I am afraid that I will damage something if I force it over the roof plug. iI it is even possible. But as it looks right now I don´t think I have to ether.



It still is a little bit more bent then the original roof but not very much. Remember it rides on the front edge in this picture.





There is still hope..

Yes that will work I guess and that was my thoughts too.. I think I can use this mold..  I will lay it on the plug to see were I´m at..   and then I will see what I can do with the surface.. 

After two post cure cycles, it really shouldn't be moving at all anymore, you could leave it clamped to the plug for months and it would do very little.

Really you are better off deciding whether you can make this mould work, or are you better off starting again. One potential option is to clamp it in place, and provided that works well, you could then bond on your planks of wood with an adhesive and some fibreglass. This may have enough strength to hold it in place again. Not ideal, but would certainly do for a one-off.

Well.. I had a propeller and got a banana..

God news is that i can´t see any traces of the warping.
Bad news is that it sagd to much and are shaped more like a banana.. 

But by just bending it a bit in the oposit direction it got a bit better instantly.. So I think I can work with that at least.. 

Later today I will lay the mold over the plug again and see if i can clamp it down and let it sit for a few days and see how it goes.

You might be right..  But i think the main cause is the weight of the mold and how I supported it..  Maybe I should have done the post cure with the roof plug and the roof mold together.. I was afraid of release issues if I did that or how the filler and paint on the plug would react.  

Another thing that would have helped is my original  ide of wood reinforcements. I skipped those because of the short put life I experienced and not knowing how those would interact with the mold during post cure.

I put the roof plug back in the oven supported on each corner and hopeing it will go back by its own weight.. It is pretty heavy and I didn´t dare weigh it down.  By a quick look at it in the oven this morning before going to work it looks alot better.   I did:

60 deg for 2,5 hours
70 deg for 2 hours
80 deg for 2  hours
90 deg for 2,5 hours

I just let it cool of slowly in the oven by just pulling the plug to the heater.   I will inspekt it more when I get home and give you the verdict.

About the oven design..  I messured the temps in several places in the oven and ones it´s heated up the temps all around it was pretty good. I don´t remember exactly but it was something like within 5 or a few deg..
 The heater is on for maybe 10 sec and then it is off for about 20 sec and then it repeats itself oven and over with the help of the thermostat.  From when the heater starts and to it shuts off it is about 4-7deg at the top of the oven.

In front of the mold and in the rear there is 20cm of gap to the oven walls so the fan can circulate the air and the fan is on 100% of the time.. But I agree it could be made better.. Idon´t think it is the issue for this though.

Looking at your pictures, it seems like the mold isn't only twisted, but also has a wrong curve along the length. Because of the double folded edge, this might make it more difficult, to get an even unwarped look during the final fit process.
To me, your temper setup seems far from ideal, with the heater directly under the mold. this way, you will get an very uneven temperature gradient over the mold, likely causing the warping. A simple solution might be to use more than one heater, ideally less powerful. Or to build a circulation channel, in wich the heater is placed.