layed up F/G over pvc board?

[bob lico]

i went to work on the 38 bertram today and came across something odd at least for me.i was installing a two ray marine 12" displays on the capt. patrick built bridge and had to make the existing display mounting cut out larger.while making the cut out i notice the dashboard was actually made up by taking 3/4" pvc board and making a fiberglass lay up directly to the pvc possibly with epoxy but not sure.has anybody ever done this before? looks like two layers of cloth then gel -cote .

[Tony Meola]

Bob

I am on a note pad so I can not copy the link, but if you go over to the old board building tips you will find it. Capt Pat used PVC foam Board insome projects.

[bob lico]

tony as you know there is Azak brand pvc all over my boat . engine box sides, side panels in cockpit,inner transom cockpit wall,water trough on either side of cockpit under gunnels how ever i never tried to ahere F/G to pvc board thinking it would delaminate over time as oppose to coos board which is made of F/G.i am about to make a new design dashboard in my 31 with two 12" displays (Furuno) facing toward the pilot instead of maintaining the angle of existing dashboard. more or less like a c-2 corvette .

[Marlin]

I have epoxied pvcnumerous times, currently epoxying a pvc pre painted backer board holding 4 ball cock manifold to my water tank wall in my new ride. Didn't want to drill holes into the tank, ground the painted area where I wanted to mount the manifold and glued the board on,held with masking tape till it kicked, in an area where there is lots of traffic and abuse so I wanted the seawater manifold to be robust. Large panels of pvc are not structural/flimsy and I found it easier/faster to go the coosa board route in these applications.the pvc doesn't hold self toppling screws well, will strip out real easy, coosa not much better

[Marlin]

I actually just did the same on my 42' with 2 new garmins, side by side, 545 and awlcraft 2000. You will find pvc dents easily in the handling/processing prior the painting, I've switched to a polyurethane spot filler that goes off quickly, no more red bondo spot filler

[Pete Fallon]

Bob,
When I was building back in the late 90's we used High Density PVC board by Michigan Composites it was 80 pound density and was 5/8" thick, The 80 pound stuff would hold a self tapper and with a layer of vacuum bagged 1780 or 1808 glass and gel coat it held without any problems. The entire 34' center console was made of 5/8" material with the exception of the bottom which was 23 layers of hand laid 1708 & 1808 with a 2-1/2 " thick PVC board in the transom. Just remember to seal around all holes and self tappers with life caulk or 4200 to keep out the water foam board will wick water into the foam over time. The 80 pound material would not dent as easily as the 40 or 60 pound stuff. Epoxy works well also on the foam board.
Pete

[IRGuy]

I use PVC board in place of wood on almost anything these days. I buy 3/4" and 3/8" 4'x8' sheets (white) and use the same fastenings I would have used on wood. While I have never needed to apply epoxy cloth onto the surface I don't see why this should be a concern. The stuff I buy from a local building supply house isn't marked to indicate it's weigh. I have epoxy coated the stuff and have painted with 545 primer followed by one or two coats of AwlCraft 2000 after the base material has cured. I have also painted it with AwlCraft 2000 without using a primer, and to be honest I don't see any short term (one or two years) benefit to the priming step.

In an effort to keep to a minimum the number of different building materials I want to keep on hand I no longer use Bondo type fillers and use epoxy thickened with different thickeners and use the paste as crack/gap fillers. I have also painted the raw PVC sheet but am careful to roughen surfaces to be painted with 180 grit sandpaper first.

I love the PVC sheet.. it doesn't need paint.. doesn't need to be sealed, won't absorb water.. and interestingly enough it floats. The only negatives I have found are that it is too soft/flexible to use in structural applications, and it does dent easily.

[Marlin]

Google PVC hygroscopic resistance, the Japanese buried it 60 years ago, still going strong. Again ,it's not structural,epoxy compliant, paintable, routerable,lite wt, I made all my cockpit inside panels /accesses out of PVC,it's easy

[Tony Meola]

Bob

I used Azak that I epoxied to the back side of the bridge area over the cabin. I thickned the epoxied and buttered the board and attached it so I could add a couple of fuse blocks and attach wiring. The first one stayed up two years before it let go. The second one I prepped a little better. Light sanding of the board and green glass. Wiped it down with alcohol. 12 months later still up.

From what others have said, looks like you can use glass mat also.

[Tony Meola]

Bob

Would love to see pics of what you do once you have it done.

[bob lico]

thank you brothers for the information on pvc and epoxy lay up ,like i said i am a big fan of Azak brand pvc board much better than box store brand with soft inside layer however i never used with a layer of cloth or mat now i see you guys also used biaxle ------wow . the Coosa board is very pouros even with the strongest B-26 style Coosa which is better than pvc for cockpit floor whereby using Coosa YOU would not see pin holes hidden under sand finish but on a dashboard the finished product must look good .i just wanted to mention i use the azak brand pvc for structual 10 years ago and it was the perfect choice. i made "strong back " which is a framing carpenters term used to hold the ceiling beams in attic together in every stick built home in the northeast. i used two pieces of 3/4" by 2" side by side glue with pvc glue then one piece of 3/4" by 1 1/2 " on the flat on top ,these are my supports for the companion way floor between engine boxes and because there is plenty of width i use 3/4" of the supports to hold my quick removal (no screws) engine box side pieces.the Coosa floor boards hold engine side pieces from moving inward and a pvc strip in engine compartment bulkhead hold the side panels from moving in like a long slot to drop panels in from top with engine covers open. these supports are in the bilge exposed to salt water all the time look like the day i installed 10 years ago.

[Tony Meola]

Bob

If I understand you correctly, you laminated AZEK to make it structural. Is that correct? I would guess laminating Two pieces together and then one on top would create a fairly strong support.

[bob lico]

exactly tony