Building a Fiberglass Dinghy or Two
This is the second layup I referenced earler. Two boats, the first one is what comes off of the plug, the second is layed up in the first, which is now the mold.
The layup schedule is very similiar to the first. Here the bottom runners are done after the hull is done. All layups are done as in the first with the exception of the gelcoat. Clean the Mold, Clean the Mold. It should be washed out and anything protruding needs to be sanded off so the boat will come out of the mold. Why am I so adamant about cleaning the mold, because I did not and we had a hard time getting the boat out of the mold. Once the mold is ready, coat it with Mop and Glo or ?? and two coats Partial, brushed or sprayed. Three coats gelcoat. I had this all ready to go in the evening so we could start the layups in the morning, worked fine. The layups were done with 20cc's cataylst per gallon resin and that worked very well. Also, due to the inside curves a 4 inch bubble roller worked better than the 6 inch.
The layup schedule is very similiar to the first. Here the bottom runners are done after the hull is done. All layups are done as in the first with the exception of the gelcoat. Clean the Mold, Clean the Mold. It should be washed out and anything protruding needs to be sanded off so the boat will come out of the mold. Why am I so adamant about cleaning the mold, because I did not and we had a hard time getting the boat out of the mold. Once the mold is ready, coat it with Mop and Glo or ?? and two coats Partial, brushed or sprayed. Three coats gelcoat. I had this all ready to go in the evening so we could start the layups in the morning, worked fine. The layups were done with 20cc's cataylst per gallon resin and that worked very well. Also, due to the inside curves a 4 inch bubble roller worked better than the 6 inch.
Now, if you run into difficulty getting the boat out of the mold, here is what we did.
First try to get it out of the mold by using wedges to separate the sides of the boat from the mold. Then take a block of wood and a deadblow hammer and pound down on the edges of the mold. I put air fittings (just tire fittings) in the bottom of the mold but with 120 psi it did nothing. We finally got the stern to part but where the hull started to curve up towards the bow it would not let go. It was not properly cleaned and prepared. My friend came up with the idea of pouring water into the mold since the Partial was water soluble. We took c-clamps and clamped onto four spots on the boat, put two boards across sitting on saw horses. Then we lifted the boat and mold up and tied them to the boards so all was suspended.
As we added water the weight, not the disolving of the partal, started to do some good. There was some popping as the boat was being separated from the mold. We continued to add water until the popping was pretty consistant. We stopped and just listened to it and finally the mold dropped off.
Then, we opened the case of beer and had beers all around.
First try to get it out of the mold by using wedges to separate the sides of the boat from the mold. Then take a block of wood and a deadblow hammer and pound down on the edges of the mold. I put air fittings (just tire fittings) in the bottom of the mold but with 120 psi it did nothing. We finally got the stern to part but where the hull started to curve up towards the bow it would not let go. It was not properly cleaned and prepared. My friend came up with the idea of pouring water into the mold since the Partial was water soluble. We took c-clamps and clamped onto four spots on the boat, put two boards across sitting on saw horses. Then we lifted the boat and mold up and tied them to the boards so all was suspended.
As we added water the weight, not the disolving of the partal, started to do some good. There was some popping as the boat was being separated from the mold. We continued to add water until the popping was pretty consistant. We stopped and just listened to it and finally the mold dropped off.
Then, we opened the case of beer and had beers all around.
The LayUp of Boat No. 2
