PVC Exterior Trim Boards - Has Anyone Used This Material Before???

I ran into this pvc trim board at HD and it looked very boat worthy.
Compressive strength seems to be high - it passes the "beat the tar out of it with a hammer" test.
Has anyone used it in a boat rebuild? Where?

Re: PVC Exterior Trim Boards - Has Anyone Used This Material Before???

Resin will NOT adhere to it, so it would be difficult to fasten it to the existing hull.

Re: PVC Exterior Trim Boards - Has Anyone Used This Material Before???

I have used a composite wood product that I think may be similar to what you have seen. The product that I used was an accessory trim piece for composite deck planking material. It is very heavy compared to wood and it has poor structural strength for its weight, so I don't think it's suitable material for building a "floor" in a boat. I experimented before using it, trying to stain it with motor oil, etc and it seemed pretty much impervious. It is soft, so it could be scratched or abraded. However, it has a woodgrain finish that if damaged, can be resurfaced easily in a few minutes with a wire brush.

The trim material that I used had about a 1-1/2" cross-section and was 6 feet long, intended to be an end cap for thicker composite deck planks. The material's extruded thickness was only about 1/4". Where I found it useful was as a replacement for the original vinyl walkway on my 1972 21' Starcraft Holiday aluminum on both the fore and stern decks. I cut the "legs" of the U-shape off in a table saw, leaving strips 1/4" thick by 1-1/2" wide that I glued to the sanded aluminum with PL Premium. It looks as good today as when I installed it about 10 years ago. It looks just like wood, even changing to a darker color when it gets wet and lightening again as it dries. It's easy to machine. You can actually chisel it easier than wood, more like hard clay since it has no grain to split. - Grandad

Re: PVC Exterior Trim Boards - Has Anyone Used This Material Before???

jones01m said:

I ran into this pvc trim board at HD and it looked very boat worthy.
Compressive strength seems to be high - it passes the "beat the tar out of it with a hammer" test.
Has anyone used it in a boat rebuild? Where?

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Looks like starboard ..

For "trim boards" do you mean shims .. or trim boards ? ..

What is the specific application ..

YD.

Re: PVC Exterior Trim Boards - Has Anyone Used This Material Before???

I use it all around my boat. I have always attached it with screws, and never tried to glue it. It works well as an upholstery retainer, as trim molding, and if you take off the sharp edge it works nicely to to keep ropes from rubbing the paint work.

Re: PVC Exterior Trim Boards - Has Anyone Used This Material Before???

Wood, adhesion and water absorbtion were my primary concerns. It sounds like you have played with this stuff before??

Grandad, thank you for your explanation. That deckwork looks sharp. I am familiar with the material you reference.

Yacht Dr. said:

Looks like starboard ..

For "trim boards" do you mean shims .. or trim boards ? ..

What is the specific application ..

YD.

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Yep, trim boards. They are for use in trimming the exterior of a home. 3/4" thick by multiple different widths and lengths.
I was thinking of cutting the stringers down in height by 1/2" and glassing over them. Then make up the 1/2" with the PVC and glass over that. A glassed ply stringer with a PVC cap. This would give me something to screw my deck down to without penetrating the encapsulated stringer. I would then remove the screws one by one and redrill the hole and fill it with a glass rod. Just a thought. I am a few weeks away from replacing my stringers.

I soaked a piece overnight in dye. After cross-sectioning the sample there appeared to be no dye absorbed. So...good with water, and cutting, but maybe not so good with bonding.

Re: PVC Exterior Trim Boards - Has Anyone Used This Material Before???

Try laying some poly resin and mat on it. I will peel right off. Great stuff for houses, Boats......Not so much.!!!!

Re: PVC Exterior Trim Boards - Has Anyone Used This Material Before???

Aviator, thanks for the tips. I'll throw my piece up in the rafters. Maybe I can use it near the end of my restore.

Wood, thanks. If it doesn't bond, I will quit persuing it for the intended application. Perhaps the non-bonding characteristic may come in handy at a later date.

Re: PVC Exterior Trim Boards - Has Anyone Used This Material Before???

It might work in a tinny where it doesn't need to bond to that fancy glass stuff,.........

Re: PVC Exterior Trim Boards - Has Anyone Used This Material Before???

I used one to replace this dash board http://i176.photobucket.com/albums/w200/ezmobee/Boat Project/DSCF1927.jpg and it worked great. I also used one for the bow deck support on the new boat http://i176.photobucket.com/albums/w200/ezmobee/New Boat/DSCF2534.jpg

Re: PVC Exterior Trim Boards - Has Anyone Used This Material Before???

OK EZ, now you've got me. That dash looks sweet!!! I went from minimal possibilities to endless. Please reign me in.
Did you fair it out with epoxy and filler? Just paint?

Re: PVC Exterior Trim Boards - Has Anyone Used This Material Before???

Do you think this could be used to create the top (flat) part of a steer and passenger console? I'm not sure how the boards would join up together. I was also thinking of covering it in vinyl but if nothing sticks to it that's not a good plan.

Re: PVC Exterior Trim Boards - Has Anyone Used This Material Before???

I've got a piece of that stuff, thought it would be great for interior cabinets. It is PVC and I thought resin would stick. I'll try it out this weekend. It has no real strength to it but maybe it would be an alternative coring material.

Re: PVC Exterior Trim Boards - Has Anyone Used This Material Before???

jones01m said:

OK EZ, now you've got me. That dash looks sweet!!! I went from minimal possibilities to endless. Please reign me in.
Did you fair it out with epoxy and filler? Just paint?

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Thanks! I just painted it. The stuff I bought had a course "wood grain" look on the one side but was smooth on the other so that side faces outward.

As mentioned it really doesn't have much strength but is great for anywhere that it's mainly just filling space. It's awesome to work with as far as drilling out for gauges and stuff like that.

Re: PVC Exterior Trim Boards - Has Anyone Used This Material Before???

So I am continuing on with my very "scientific" experiment. It passed the beat the tar out of it test.

High compressive strength - High

A six foot piece when held flatwise deflects about 1 foot

Stiffness - Low

The next test was the water absortion. It was held 24 hrs under a pool of water with dye (food coloring). The end was left with a cut surface condition. I had no microscope to see really close, nor a fine scale to weigh before and after, however it didn't "look" like the dye extended past the exposed edge. (Pictures Below)

Water absorbtion - Low

Mr. Wood says no sticky with poly

Poly compatability? - No

Next test is to determine epoxy compatability. I got really scientific here and very precise with my measurements. I took the cap off an epoxy container and mixed my epoxy 3 caps to 1. I then cut a small "tensile sample" with my very precise boxcutter and set it between a piece of marine ply and alder lumber. Neither had pre-applied resin so I am a bit concerned about absorbtion into the wood prior to the bond. We will see... like I said it is very scientific. I am feeling a bit Stephen Hawkingish. some pics below.

Dunk and Dye for 24hrs


Cross-section after dye


Tensile test sample - I sure hope the parent material fails first when I place it in the load cell (me pulling really hard)

Re: PVC Exterior Trim Boards - Has Anyone Used This Material Before???

I have used this stuff before. It's most commonly known as Azek. The biggest problem I had with it was, the excessive expansion and contraction rate.Really is very temperature sensitive. An eighth of an inch movement is not uncommon in an eight foot board.

Re: PVC Exterior Trim Boards - Has Anyone Used This Material Before???

ok mr hawking.......get out of that wheel chair and tell us what happened with the epoxy........epoxy is great glue.....i would be suprised if it didnt bond somewhat....but under full stress i think it will fail due to the nature of the material.

but....lets see !

Re: PVC Exterior Trim Boards - Has Anyone Used This Material Before???

*EdC* good point on the thermal expansion! Depending on the region one may see a 100deg F temperature change. PVC thermal expansion coefficient is .000028 in/in*F. For a 96 in. board and the temp change you would see .27 in. change in total board length. Reinforced fiberglass has a coefficient of approximatey .000014. Differential expansion may be an issue.

Thermal Growth - High

Oops!, I am hopeful on the bond strength, but my hopes aren't too high. I will wait until Saturday to test. I think the Alder may have soaked in too much resin. I couldn't apply enough resin to the endgrain to keep it satisfied. It just kept sucking the resin in. So, I set it flat.

Re: PVC Exterior Trim Boards - Has Anyone Used This Material Before???

OK the pull test results are in!!! I have to start by saying that I made a bit of an experimental blooper as I didn't complete sand off the surface I had exposed to water. You can still see the blue surface after breaking the part in tension. And... actually you can see the blue in the above picture prior to bonding - what a dope. However, I was extremely impressed with how well this material bonded with epoxy. I really took some pulling to have this seperate.

Pull Test Results

I place my feet on the marine ply and simply pulled vertically until failure. It can clearly be seen that the fracture was through the parent material (PVC) and part of failure was at the bond line. I do believe the bondline failure was due to me touching the previously wetted surface several times.

The piece still remaining on the marine ply I pryed over at the top pushing parallel to the plywood. Again it was difficult to pry over but the failure was in the marine ply, not the bond line, nor the PVC.

I conclude that this material bonds well to an exposed core surface. I did not test the bond strength of the smooth finished surfaces.

Conclusion:

Compressive Strength - High
Water Absorbtion - Low
Thermal Growth - High
Bond Strength - High (with epoxy on porous surface)

You make the call where it can be used!

By the way, EZ, I would love to know what type of paint you used on your dash.

Re: PVC Exterior Trim Boards - Has Anyone Used This Material Before???

jones01m said:

By the way, EZ, I would love to know what type of paint you used on your dash.

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I used Rustoleum but the bond wasn't super great. I think the plastic paints like Krylon Fusion or equivalent would be the ticket.