You know, I’ve dealt with vacuum bags and all of their good and bad points for years and have always tried to figure a simpler way of applying pressure to a laminate or a laminate core without the bag and the pump and the pressure gauge and the tape and the… Setting up the bag, getting the board inside without mucking it up. Trying to get the pieces lined up through the bag. Getting the pressue right. Finding the damn leak in the bag. I’ve also used clamping systems and sand boxes and pressure forms. Geez, ain’t there a simple way to do this!? So I’m fixing a ding the other day and I needed to put some pressure on to hold a piece in place. I went to the kitchen and got a 1 gallon zip lock bag and filled it with some sand from Home Depot, put a piece of plastic over the ding and set the bag on. Worked great. A couple weeks later I had a veneer laminate to set onto a piece of plywood and used the same method, this time with many bags of sand. Again, great results. After seeing this, I wanted to inlay a veneer on the deck of a board using the same method. Needless to say, worked like a charm. Now, finally, a simple way of attaching veneers, laminate cores and a way of lowering resin content in epoxy laminates without the hassle.
My grandfather was a furniture maker. I spent endless hours in his shop with him, growing up. He had a whole pile of little blocks, wrapped in newspaper and taped with ancient yellow tape. Once I asked what they were and he said, “Old carpenter’s secret special clamping tools.” He slit open a block to expose the present inside…a brick.
Now I have secret special clamping tools, too. Here they are working on some stubborn air bubbles:
When I was building my yacht,I had to do carbon laminates on the rudder blades
I had no bag material left so I got two peices of 4" sponge foam put one peice on the floor with some glad wrap over laid the laminated rudder blade on top then more gladwrap over that and finally the other peice of foam
Then a sheet of ply with some weights (buckets of water) on top
The sponge neatly fitted the camber of the rudder blade and gave equel pressure all over the blade
Worked a treat i have used this system many times since then, all ways works and is cheap and reusable
good trick greg. we use bags of rice from costco. the conform perfectly to any deck or bottom and apply good pressure for delams or splits or anything you need to glue back down.
Oh yes - rocks, scrap formica to smooth out a curve, sometimes a stick wedged to the overhead ( old boat guy trick), the odd chunk of iron that is kept around the shop for just such occasions. Scrap lead, recast in old coffee or tuna cans - Gravity is a beautiful thing…
I’m thinking of using a system where you could lay a tarp over the board and fill a large all round hem with water for weight. Sort of like an upturned blow up kiddies paddle pool with the ring filled with water instead of air.
That would give even pressure coverage as long as it was level and well supported.
Theyre all handy... Ive used hand-sized sand, bricks, cast iron, steel cut-offs, etc.
But my favorite is lead. I currently use little blocks (about 1 1/4" x 4" x 3") wrapped in duct tape… 6 lbs. each. Various sizes of small bags filled with lead buckshot and/or 1/4" diameter balls and sand are really useful, too.
the contrary minds eye saw a weather baloon taped to the surface and inflated hmm opposite of vacum - air pressure hmm … ambrose … my brix are from the old boiler at the extinct sugar mill that were dumped over the cliff next to the beach and weathered for 40 years or so like rounded corners and the cement between still stuck like three bricks thick…an another just two but beach polished
My shaping brick is from the base of the Cape Hatteras lighthouse. I got it when they moved the lighthouse in 1999. They dug under the thing and lifted it on hydralic jacks. A few of the bricks from the original foundation were scattered about. Gotta have classic tools.
If you really want to make life easy go to the beach and fill up a bucket with sand. Plastic bags of different sizes filled with sand conform to what ever shape you want them to and several courses of masking tape on a sheet of brown paper to give nice even pressure over the whole surface with a piece of mylar under the sandbag can be pretty effective for getting all the bubbles out of concave or flat surface. Convex surfaces need a little different approach as they to be open at the ends to bleed the gas off so forget the tape and work by building a damn around the perimeter of a piece of mylar that conforms to the area you’re working. Build the mound of sand starting from the center and adding it gradually. Dry beach sand is a magical way to capture gravity and put it to work as a subsitute it for a vacuum.
Irregular surface present the extreme challenge and take quite a bit of creativity to get the air out without the use of vacuum baging.
I can see the writing on the wall for polyester since my glasser recently suffered a price hike of 25% for a drum of Lam. So, I commenced gluing up sheets of polystyrene sqeezed to a rocker using my personal board with the fins removed. That being sucessful, I began flashing on how to reduce the amount of epoxy required to glass the fucker… Veneer laminate, maybe even kitchen bench laminex, but I forsaw loads of asspain with the vaccum bag thing! So I figured a deck insert was a good start, no need to wrap it around the rails. Sand bags occurred to me, but here’s another for you. How about a type of chainmail blanket, you get it, like lead links in a big floppy mesh. Or, the bubble wrap type stuff with cells filled with leadshot instead of air?
Tell you what, if that stikes the right note with you, you can send some of the resin research epoxy to me here in Australia!
