Hey Magenb, are they made out of balsa wood? If so, you really want to stay away from really wet sealers or primers. It soaks it up to much and can warp. In the past I made warhammer ships with popsicle sticks and balsa wood. The best thing I found was automotive spray primer.when I used regular primer the wood would warp but with the auto one it seamed to dry faster and not absorb but you have to mist it,not a one pass thing. Mist it on, let it set for about 10 minutes then mist it again and repeat once more. It worked great for me. Hope this helps. Also might look into Kilz at a hardware store or comparative brand made for wood work.