Laminating

[BLueOne]

I was wondering If any one could help me with a question. I bought a hull off of a builder, hull and stringers only, I was wondering if I can add more laminate to the hull ? do I have to grind it it smooth? and how many layers of laminate is safe to put dowm at one time ? mat-1708-mat- 1708-mat would this be ok with out to much heat? thanks

[Eric Sponberg]

BlueOne,

You should be able to add more laminate, but you will have to grind the existing surface very well with coarse grit sandpaper. Don't just kiss the surface, go over it thoroughly. Wash the dust off the surface with water, then wipe down the entire surface with acetone to get every last bit of contaminant off the surface.

I presume that the laminate is made with polyester resin. Other polyester can go on top. Try to use a similar brand. Polyesters come with different physical properties. Vinylester (twice the price of polyester) can also go on top. Vinylester sticks a lot better than polyester in secondary bonding, which is what you will be doing.

The amount of resin to use is a function of how fast you can work it into the laminate. With many hands (a number of helpers) you can laminate large areas. By yourself, you will have to work in smaller areas. It is best to start with a small area, see how it goes, then expand to larger areas in steps until you get used to working with the materials. You should be able to put down two layers at a time. However, if you are covering the entire bottom with two layers at a time, be sure to stagger the joints so that adjacent panels will join with staggered butt joints. For example, when all is finished, the joints in the second layer should be staggered at least 2" away from the joints in the first layer.

The drawback of going down with too many layers is that the heat of exotherm on a thick laminate can burn itself and the substrate. You'll know this if the laminate starts to visibly smoke! If it does, the new resin will turn brown and the laminate will be ruined. You can do a test panel say a foot or two square just to try it out first before you go onto the hull proper.

Eric

[BLueOne]

Thanks Eric,I really appreciate the advice . I plan on grinding the hull with 50 grit to get it down good and smooth Thanks ALOT

[bosko]

i built autos for 20 years steel ,mold, tooling etc and i suguest that you use no less that 16 grit for better and longer grip to existing finesh. it will only last as long as the care taken to apply it. there is realy no bond but the shrinking around the edges of the sanded area and 16 grit makes a good edge also don't forget to change your good guality sand paper often (dull paper makes shiney edges and you want crisp gouges for the new resin to adhere to)

[BLueOne]

Thanks For the adVise guy's I really Need all the advise I can get . I decided that It would be to much work to Laminate More glass on so I sprayed it with gelcoat and hope for the best. After drilling the rear drain hole Below the transom core the glass was about 3/4 of an inch. Great web site I have learned alot