mirror finish on mould

Hello,

sorry it has been probably asked already by someone else, but for Fibreglas boat building, what is the technique of getting a mirror like finish on the hull?
We have a mould, but then again, there are enough imperfections and we also look of buidling maybe another mould, so could someone explain me, how to achieve a semi pro looking shape???

Thanks for your your time
MIKE :?:

 

Mikeskip, usually the mold will only look as good as the plug that it was made from. It is much easier to get the plug right to start with than it is to repair a mold. Once the proper shape of the plug in which you wish to make a mold from, is correct, primer it out with Duratec gray high build surfacing primer. Add the clear gloss additive to reduce porosity and give higher shine. Wetsand to Duratec in varying grades of sandpaper and progress to a much finer grade, such as 320 to 400, 600, 1000 and then to 2000 to remove all imperfections. Then buff with a 3m fine compound then polish out to a mirror finish. Now this perfectly shined plug will translate to the mold. You will still have to buff the mold before puling a part from it to remove any pva or other releasing agent used when pulling the mold from the plug. Fiberglast developments has some great toturials on their site from begining to end of the full process from plug to mold to finished part.
-Aqualoco

 

Hello Aqualoco,

ty for your answer. But is there no easier way (e.g. Nylon Panels or similar), because you will still end up with imperfections and the final result is only visible, once you made the hull!

MIKE

 

Mikeskip, boatbuilding is labor intensive hard work. there is no miricale procedure to get a mirror finish other than good ole fashioned hard work. Even if the plug was CNC machined it would still most likey have to be sealed with something then buffed out and the for the mold that would be pulled from it would have to be buffed as well. Face it. it's hard work. IF YOU WANT TO TAKE THE EASY WAY, TAKE THE HIGHWAY and dont start a boating building business.

 

Hi Mikeskip,

Aquoloco's right.
Whatever you do it will require hard work and money. If you already have a mold that is not to your standard, then hard work is the only way out.
However, it depends on what you mean by "imperfections".
If it is scratch's and gouge's in the mold surface, then doing repairs on the mold is relatively easy. Likewise if the tooling gelcoat is in poor condition.
If it the mold surface is not fair, then you have a bigger problem. Depending on how unfair it is you could either fair the mold (a skillful thing to do) or take a part from the mold, fair it, and build another mold. Fairing a large thing well is an art in itself. Seperate from painting.
There is no easy answer to your question.

Good luck,
Rob

 

Also, I forgot to add, it depends on whether you want just one fair boat, or do you want the result to be a production ready mold.
Rob

 

Mike,

Buff your mold, then use water sandpapers on the hull starting with 600, suggest not less grade, then 1000 and any of the polishing paste - Farecla is one of the best. Makes mirror on the hull after 1000. I have a lot of experience with buffing mould and hull. -)