Gas Tank Hatch Recore

[hansk]

Hello I'm about to take on this project for the first time. Starting with my auxiliary hatch witch is 25"x52.5". A lot of good information here but can anyone suggest how much resin I should be looking to buy? I have the hatch gutted of the soaked plywood squares and ground fairly smooth.

I would like to add a layer of 1708 to the shell before glassing in the core. I will be using a piece of 1/2" ap ply for the core and cutting it back from the inspection holes and edges about an 1-1/2" as others have done. As far as adding material into the channels would just laying strips of 1708 in or thickened epoxy be best? Not sure which filler I should chose. 2 layers over the core sounds like everyone's final step.

The prices from US composites are nice and would like to go with the epoxy. Just would like to know how much it took for others so I can order the right amount.

 

[ROBERTH]

I ordered the 3 gallon kit from US Composites with their 1708 biax with mat. I did 2 panels, total was approx. 6' X 4' and used about 2.5 gallons of the epoxy resin, not counting the hardener. YOu might get by with 2 gallons, but if you get some extra, you will have some epoxy laying around for other use. I am using some small squares of the 1708 with the epoxy to backup some of the screw holes that are stripped out.

Instead of cutting back so much wood from the edges or center, I used a grinder to taper at a 45 degree angle and left more of the wood to the edges for support and strength. I just made sure I drilled or ground out around any area that the screws would come through so they would only be exposing water to epoxy and not any wood.

I did not have to use any filler. I used a wide putty knife to press the 1708 down into the edges so they helped fill in the void, not to mention that is a very strong edge now due to the glass approaching the edges coming in at a 45 degree angle and then going vertical with the epoxy filling in what area is left.

I think it is a great idea to put a first layer down for strength and screw holes next to the panel layer.

Since Ply is stiffer than the balsa as balsa is many tiny squares, make sure you add extra epoxy down before laying in and then weight it down to get the air out from underneath as best as possible, then proceed with final layers. Also make sure you have good support under the panel when laying the glass so it has a solid surface to press against or you will still get air pockets and/or bulges in the finished product.

 

[hansk]

It's looks like we may have some warmer days next week so I'm getting ready to start the job. I was able to get a piece of balsa core from work and beveled the edges down. I would like to lay down a layer of 1708 first then "hot lay"? The balsa down and weigh it down and let it cure. My question is should I pepper the core with holes for air to escape or is this not necessary? The balsa was a piece of scrap so it has a couple holes around the edges as it is