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Login to post Forums » Off-topic discussion » Sealing plywood

Sept. 12, 2011 12:59 p.m. joey48442 SuperDork

I made my own tonneau cover for the danger ranger, and it turned out well. But, I used quarter inch plywood for the surfaces, and painted it heavily with an indoor/outdoor latex paint. But, now it seems to be sucking up water. I dont want all the ply to delaminate itself. Any idea how to seal all this up? I was thinkning of wrapping it all up with ice and water sheild that you use on the roof, but its about 50 bucks for 150 square feet, and I only need 40. Trying to stay on a budget here. Any ideas? JMFNB suggested indoor/outdoor carpet, put the fellas at home depot said the water would probably still get through.

Help! Trying to keep this cheap!

Joey
Sept. 12, 2011 1:02 p.m. fromeast2west New Reader

You need some type of sealer that will penetrate. Look for deck sealing and conditioner.

You could also try glassing it, but at that point any future flaw in the fiberglass that allowed moisture in would also trap it and lead to localized rot.
Sept. 12, 2011 1:07 p.m. SVreX SuperDork

I'm afraid your initial choice of material wasn't so good.

1/4" ply is probably not exterior grade. It will do everything it can to soak up water and delaminate.

Additionally, the latex paint isn't helping you any. Oil based would have been better.

Second best option will be to paint, paint, and repaint- especially the edges. Include the back.

This may become a source of frustration for you. Sorry to be the bearer of bad news.

Best option may be to replace the 1/4" plywood with a water resistant material, like sheet plastic, marine plywood, fiberglass, or metal.
Sept. 12, 2011 1:08 p.m. SVreX SuperDork

fromeast2west wrote:

You need some type of sealer that will penetrate. Look for deck sealing and conditioner.

You could also try glassing it, but at that point any future flaw in the fiberglass that allowed moisture in would also trap it and lead to localized rot.

Penetrating sealer is going to have a tough time getting through that latex paint.
Sept. 12, 2011 1:11 p.m. joey48442 SuperDork

SVreX wrote:

fromeast2west wrote:

You need some type of sealer that will penetrate. Look for deck sealing and conditioner.

You could also try glassing it, but at that point any future flaw in the fiberglass that allowed moisture in would also trap it and lead to localized rot.

Penetrating sealer is going to have a tough time getting through that latex paint.

Yeah, I was afraid my choice was not the best. Maybe I could sand the edges, and repaint with oil based paints. The ply I used was cheap, so no big loss there. Maybe I could try coroplast. Im mainly looking for aerodynamics here, it doesnt have to be very strong. That and keep the contents a little hidden.

Thanks for the advice.

Joey
Sept. 12, 2011 1:16 p.m. Graefin10 HalfDork

You're going to have to strip the latex off and then I'd put one layer of fiberglass cloth on it, sand it and put another coat of resin on it. That will last for a very long time.
Sept. 12, 2011 1:31 p.m. Cone_Junky HalfDork

In reply to joey48442:

Aerodynamics? Mythbusters de-bunked the tailgate down, tailgate net, and tonneau cover giving better MPG myth.

But not having a toronado in your bed and hiding it's contents definitely has it's use.

The edges of the plywood are definitely the weakest link. Seal them up and you may buy some more time.
Sept. 12, 2011 1:57 p.m. donalson SuperDork

I paid $30 for my Leer fiberglass topper... kills the pick up "look" and not as subtle but makes it fairly usable :)... well when the truck runs it will...

so might keep your eyes open on craigslist :)...

if you keep with the current tonneau then follow with these other guys :)
Sept. 12, 2011 2:01 p.m. joey48442 SuperDork

Cone_Junky wrote:

In reply to joey48442:

Aerodynamics? Mythbusters de-bunked the tailgate down, tailgate net, and tonneau cover giving better MPG myth.

But not having a toronado in your bed and hiding it's contents definitely has it's use.

The edges of the plywood are definitely the weakest link. Seal them up and you may buy some more time.

Yes and no... The tailgate down thing, yes, I agree. But the tonneau helps.

Joey
Sept. 12, 2011 2:24 p.m. DeadSkunk Dork

Got to Joanne's Fabric and price up some vinyl sheet. You could glue it over the plywood with contact cement.
Sept. 12, 2011 2:28 p.m. alfadriver SuperDork

DeadSkunk wrote:

Got to Joanne's Fabric and price up some vinyl sheet. You could glue it over the plywood with contact cement.

While you are at it, you can also do the cab for a fake convertable look. that would be bitchen.
Sept. 12, 2011 3:02 p.m. ClemSparks SuperDork

Cone_Junky wrote:

In reply to joey48442:

Aerodynamics? Mythbusters de-bunked the tailgate down, tailgate net, and tonneau cover giving better MPG myth.

But not having a toronado in your bed and hiding it's contents definitely has it's use.

The edges of the plywood are definitely the weakest link. Seal them up and you may buy some more time.

I haven't seen the mythbusters but I HAVE run two passes down the dragstrip (many years ago) back to back in an elcamino with the only appreciable difference being the position of the tailgate (one time it was up, one time it was down). I noticed a significant difference (I believe it was a couple of tenths) in ET.

The resolution seemed appropriate since the car was so consistently slow (I think it was running in the 16s or something). The sample size was pretty low, but I consider it conclusive enough to be worthy of a lifetime of anectdotal evidence.
Sept. 12, 2011 9:46 p.m. wlkelley3 Dork

The Mythbusters did their test on modern pickups that are designed for mpg with tailgate up (and windows closed also, a different mythbusters test). Older less areo trucks do benifit slightly. El Camino probably does too.

Cover the wood with some black vinyl (be sure to wrap edges) and it should look like the $$ vinyl tonneau covers but give more security.
I know its more $$ but perhaps coating it with some type of resin. For the GRM approach - varathane from the hardware store. For the $$ approach - fiberglass resin.
Sept. 12, 2011 10:13 p.m. EvanB SuperDork

Cone_Junky wrote:

In reply to joey48442:

But not having a toronado in your bed and hiding it's contents definitely has it's use.

I just want to see a Toronado in the bed of a pickup.

I'm sure all that weight wouldn't help gas mileage though.
Sept. 13, 2011 8:18 a.m. pilotbraden HalfDork

An epoxy or polyester resin would seal it.

http://www.dickblick.com/products/castincraft-clear-polyester-casting-resin/

http://www.westsystem.com/ss/

A good source for vinyl tarps are billboard companies. They are 14' x 48' and range from free to $20.
Sept. 13, 2011 8:44 a.m. 914Driver SuperDork

Decopage? A two part resin that seals cloth and stuff to wood, it's a hobby for some. I've seen it on a home made bar top, pennies all over the bar then encapsulated in the clear resin.

I used it to seal car arm rests I made out of Zebrawood.
Sept. 13, 2011 2:20 p.m. joey48442 SuperDork

EvanB wrote:

Cone_Junky wrote:

In reply to joey48442:

But not having a toronado in your bed and hiding it's contents definitely has it's use.

I just want to see a Toronado in the bed of a pickup.

I'm sure all that weight wouldn't help gas mileage though.

Here is a Toronado WITH the bed of a pickup... http://2.bp.blogspot.com/-LeZiPSzIiUM/Tj5umCNmWpI/AAAAAAAAEbA/zgM5w7YhrBA/s1600/to...

Joey
Sept. 13, 2011 2:48 p.m. ThePhranc New Reader

In reply to DeadSkunk:

Just dealt with that for my interior where it came unglued due to heat.

A good building material instead of 1/4 ply would be a 10mm PVC sheet. Its light and very workable.
Sept. 13, 2011 3:19 p.m. Cone_Junky HalfDork

EvanB wrote:

I just want to see a Toronado in the bed of a pickup.

I'm sure all that weight wouldn't help gas mileage though.

Got spoiled by autocorrect. Illiterate without it apparently.

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