I got tired of lifting weights to layup wings and also don't like the work of taping and bagging for vacuum.
I also like to precut all holes and vac bagging can create some distortion with the end cutouts.- So - No vac bagging.

I went to the metal supply shop and bought a bunch of 1x2 rectangular .083 wall steel tube and
some 1/2" dia all thread and some springs which were 2" tall and compressed to 350 lbs .


Today I tried a lay-up on some 1000 sq in panels - the clamp I made has three upper cross pieces,
three lower cross pieces and two upper and two lower spanwise (lengthwise) pieces of steel.

The cross pieces are drilled on the ends to allow the all thread to drop thru. All pieces stand on edge -
(funny but they do not tend to flip over ) So I have a big, adjustable pressure clamp now -which clamps
at the ends and the center of a panel.

The load is evened out along the two upper and lower spanwise pieces of steel.

The wing layup is between two pieces of 1" thk chipboard and the clamp simply squeezes on them

Here is the nifty part -- you hand snug all six points--then swing the wrench -say 4 turns on each
bolt (all thread) and watch the spring on each one compress!

The spring compression at each point tells you how much squeeze you have. A 2" aluminum straightedge can be dropped
on the boards to check for bow - You can sight down the top of the steel cross pieces and instantly see if there is any twist.




The table is only supporting the weight of the parts -so more loading does not change or bow it.

Using three cross clamps I can -if I want to --exert a known 2100 lbs of total clamping force .

On a 1000 sq in panel - this =2.1 lb per sq in.

IF --I added another cross clamp piece, I could increase pressure by 700 lbs!

The amount of adhesive used (I use laminating epoxy) can now be reduced.

For smaller panels - just clamp at lesser pressures. A little basic math will keep it all in line.




Here is another photo - showing use on a highly tapered fin/rudder for a 37% Sukhoi. I used 17 grams of epoxy and clamped it to about 4psi.



The whole works cost me $50.00

For some guys -bricks work just fine - but I wanted something I could really clamp with!!

Besides - 2800 lbs of bricks is a pretty big stack.

Dick Hanson