Solvents ate my Royalex (or not)

[Guest]

Remember this silly part of the last experiment?

Since I had the Vynabond out another experiment seemed in order. I took a piece of intact RX and laid a small puddle of Vynabond on it, lightly scarred through the vinyl skin in another area and puddled some Vynabond there as well, both covered with wax paper to help trap some solvents. Might have to try that “Solvents ate my canoe” with a scrap of minicel and puddle of Contact Cement as well.


P4140001 by Mike McCrea, on Flickr

With the Vynabond puddles left on the Royalex for a week the RX appeared and felt the same. I cut those test pieces in half at the Vynabond puddles for some inner RX foam core inspection.

P4160002 by Mike McCrea, on Flickr

Didn’t do squat to either scarred or unscarred Royalex. Bupkiss that I could discern, inside or out.

Neither Vynabond puddle, on the intact or scored & scarred vinyl, had any visible or tactile impact on the Royalex, even in cut in half inspection. I really thought there would be some evidence of solvent degradation. Maybe I didn’t score the Royalex deeply enough, or maybe the Vynabond puddle solvents escaped through/past the simple wax paper squares.

Time for another, better (or worse RX condition) test.

I drilled, chisled and gouged some pieces of Royalex, in places well into the foam core.

P4190005 by Mike McCrea, on Flickr

One gouged RX test piece got a puddle of Vynabond, covered with a scrap of exercise flooring cover, one piece of RX gouged the same way got a puddle of Contact Cement and foam cover.

P4190006 by Mike McCrea, on Flickr

Both test puddles immediately covered with scrap foam. I taped the foam down on both test pieces with Gorilla tape, to help prevent any solvents from escaping.

P4190008 by Mike McCrea, on Flickr

(Looks like Joel’s new floating wallet design)

One gouged and chisled RX piece went outside the shop on a stump, where I just poured a puddle of Acetone on top to fill the divots.

P4190013 by Mike McCrea, on Flickr

Eh, I poured acetone on that test piece twice, it evaporated fast. The second time when I took the potential bottle bomb of a glass pickle jar with submerged acetone outside the shop

Yeah, what the heck, absolute crazy harshest test, a couple pieces of Royalex submerged in a half inch of acetone in a pickle jar, so that there was 4” of Royalex above the acetone line, to see if/how anything creeps up the foam core.

P4190015 by Mike McCrea, on Flickr

I’ll give all those test pieces some time, and then inspect them/cut them in half. Although my expectation is that I’ll see something funky in the pickle jar soon enough.

Any guesses?

 

[Steve in Idaho]

What I've heard form others Mike, is that if you don't allow the contact cement plenty of time to dry to tack before applying whatever covers it, the foam core will get brittle over time, faster than the rest of the hull. The rest - I have no clue. I did have one canoe for a while that looked like a previous owner must have left a puddle of solvent on the floor long enough for the vinyl to bubble up, but again - no idea what it was.

 

[Glenn MacGrady]

My first major was theoretical physics, not experimental physics, which means I've never had any tools or equipment in my life, and all I do is think or doodle on paper rather than actually doing anything. So, my initial theory is that something called Vynabond, made of methyl ethyl ketone and dimethylformamide specifically to repair vinyl plastic and to adhere vinyl to vinyl, would not dissolve the vinyl plastic outer lamination of the composite material called Royalex, Oltonar and perhaps some other things.

As to whether any of your experimental chemicals will behave rudely with the black ABS lamination or the central ABS foam of the multi-laminate composite, I have no thoughts, other than to use the correct terminology for the different lamination materials. My second major was English.

My ultimate and final major was Budweiser. I know for sloppy dang sure that that didn't dissolve any canoes in the 60's, 70's or 80's -- just the majority of my cerebral neurons. Only my lizard brain remains.

But it still thinks this stuff's better'n than Netflix, perfessor.

 

[Guest]

As to whether any of your experimental chemicals will behave rudely with the black ABS lamination or the central ABS foam of the multi-laminate composite, I have no thoughts, other than to use the correct terminology for the different lamination materials.

I am unclear about the preferred terminology for Royalex composition, and some discussion with those more knowledgeable might be helpful to all. Terminology or other corrections please:

The outermost layers of Royalex are the vinyl skin. On R-lite/R84 I believe that the outside layer is acrylic, not vinyl. The acrylic is thinner than vinyl, weighs less, and scratches through easier, but is more UV resistant than vinyl. Note: I may have the R-lite/R-84 names wrong; some Royalex billed as “light” does not incorporate an acrylic skin but simply uses thinner sheets of standard Royalex. It would be interesting to know which manufacturers used an outer acrylic skin in their lighter Royalex construction.

The next layer, on both sides of the vinyl skin is the ABS (Acrylonitrile Butadiene Styrene), an amorphous polymer thermoplastic substrate.

Inspection of some Royalex sheets from a Dagger Caper and a Mad River ME shows that those ABS layers are usually but not always black or at least very dark in color. More interestingly the ABS layer on Royalex sheet cut from both canoes vary in thickness depending on the area on the hull (as does the foam core), are consistently thicker next to the outer vinyl skin, and nearly imperceptible next to the inner vinyl skin. This is consistent with visual inspection of Royalex when replacing gunwales, although in that inspection only the sheerline edge, where the Royalex substrates are typically thinnest, is visible.

The center of the Rolayex sandwich is the unicellular foam core. A factory fresh foam core takes a year or so to fully harden.

We have an RX Wenonah Wilderness that arrived day’s old from the factory, a canoe that was immediately put into use on multiple trips, tied to roof racks with ropes and trucker’s hitch belly lines. The belly line hitches left dents where pressed against in the still-soft Royalex. A series of dents from where we tied it on the roof racks on different vehicles with slightly different spacing. The foam core has since hardened, and rope hitches no longer leave dents, but those original dimples are still visible 10 years later.

With the terminology up for review and clarification, back to the Royalex solvent abuse test. Starting with observations made and photographs taken a couple of weeks ago, during or a few days after the solvents were applied.

That expectation that the RX in pickle jar of acetone would quickly show results was confirmed. I kept an eye on those acetone soaking pieces of Royalex for a half hour or so before I moved it outside, and then got distracted with other shop projects. Two hours later the pickle jar had bits and pieces of foam core floating in the acetone and the vinyl skin was peeling back.

P4210008 by Mike McCrea, on Flickr

When I opened the jar to extract them even the top edge of the RX pieces was soft and mushy. The foam core definitely will wick solvents. 4 ½” tall RX in a half inch of acetone, funky soft all the way to the top.

Left to “cure” outside the jar the top few furthest –away inches of the test RX re-hardened over a few days time. The RX foam core is still mushy pliable soft a couple inches up under the intact vinyl skin. The bottom inch, where the vinyl peeled back exposing the inner substrate, is starting to re-harden before the still vinyl intact areas. By day 3 out of the jar that extremis suffering slice of RX was still soft in places under the intact vinyl skin; the intact vinyl skin in the middle definitely trapped and held acetone longest.

I’ll let those acetone soaked pieces sit air-exposed to see how long it takes/if the foam core eventually harden, and then try some impact or other abuse.

Next up, time to cut the Gorilla tape and remove the foam from the Vynabond and contact cement samples on the royally abused Royalex pieces.

P4210011 by Mike McCrea, on Flickr

I may have waited a couple days too long to inspect that Royalex, both pieces underneath the foam have re-hardened and do not feel mushy, or even adhesive sticky. But the exposed core isn’t compressible foam anymore, it has all the flexibility of concrete.

No evidence of vinyl skin blistering or lifting on the backside of the Royalex either sample.

P4210013 by Mike McCrea, on Flickr

The piece of abused RX with acetone simply poured into the divots and left to evaporate is much the same, if noticeably less glazed-foam shiny than on the Vynabond or contact cement pieces covered with taped down exercise foam. Nothing is apparent on the backside vinyl there either.

P4210015 by Mike McCrea, on Flickr

This has so far largely been an unrevealing shop experiment, and I’m not sure what to do next. Smash them with a hammer to see how they respond to impacts? Bend the RX pieces back and forth to see if they snap? Suggestions or ideas, other than that I have too much time on my hands?

I will band saw them each in half at the abused solvent puddles for some inner core inspection.

 

[Glenn MacGrady]

Banter aside, I was suggesting that the question of whether X will damage Royalex is not specific enough because Royalex has three different components. The questions are whether X will damage vinyl layer, the solid ABS layer or the ABS foam core. Since almost all attachment gluing would be done on the vinyl layer, I think your experiments revealed no damage there.

I envisage glues going onto the solid ABS layer or ABS foam only in the case of trying to repair a deep gouge or hole. I don't know why anyone would try to fill a gouge or hole with Vynabond or contact cement. It's more likely that an epoxy such as G Flex would be used. You didn't test that, but there have been reports of successful small repairs of Royalex damage using G Flex. Maybe from you. I forget. Neurons. Beer.

As to pickling anything in acetone for days . . . EEEEK! Someone else did that. Dahmer? Gilmore? Blofeld? Frankenstein? I forget. Pickled neurons.

 

[Guest]

Banter aside, I was suggesting that the question of whether X will damage Royalex is not specific enough because Royalex has three different components. The questions are whether X will damage vinyl layer, the solid ABS layer or the ABS foam core. Since almost all attachment gluing would be done on the vinyl layer, I think your experiments revealed no damage there.

I see no evidence of Vynabond or contact cement damage to the vinyl layers, except for the pieces which were submerged in acetone, where the vinyl skin peeled back. That said most examples I have seen have been from adhesives (not sure which) used to adhere D-ring pads or minicel to the inside of a canoe.

One message board poster admitted that a can of acetone that tipped over and leaked essentially “ate his boat”. Another (sloppily?) used MondoBond for outfitting purposes with the same result.

Beyond those and other end user reports back when I had routine contact with some RX canoe manufacturers the subject of solvent/adhesive damage came up and I was told that the manufacturer received complaints every year of damage to new canoes from folks who had attempted DIY outfitting.

As far as which layer of Royalex is damaged by solvent exposure I may know more when I saw the test pieces in half.

There is a clue about that visible in this photo

P4210008 by Mike McCrea, on Flickr

 

[Glenn MacGrady]

As far as which layer of Royalex is damaged by solvent exposure I may know more when I saw the test pieces in half.

Well, I was never much good in chemistry, but I'd be surprised if Vynabond or contact cement could penetrate through the vinyl to the underlying ABS layers. But the experiment will always have the final say.

There is a clue about that visible in this photo

P4210008 by Mike McCrea, on Flickr

Oy vey. Soaking anything in a sealed beer keg of acetone for days is unrealistic. It is (to make up a phrase) a timeperiodo ad absurdum. It really reminds me of those "cleaners" from the KGB who dissolve dead bodies in a bathtub full of acid. Thin applications of acetone in any real world, normal use, like dissolving fingernail polish or wiping a surface, is harmless to most things, and it evaporates almost immediately.

I've used acetone a lot to clean the insides and outsides of my composite canoes. It's the best remedy I've found to get rid of the white amine blush that forms from moisture on the inside of Bell black gold canoes. I suppose if you spilled a big container of the stuff inside a canoe and didn't try to soak it up, it might do some harm.

 

[Guest]

Soaking anything in a sealed beer keg of acetone for days is unrealistic

Unrealistic, but revealing none the less; note the thicker outer-skin ABS layer turned to goo in that photo. I too use acetone for some purposes, even Royalex surfaces to prep for D-rings and minicel; it flashes off quickly if applied with a damp rag. But I will not get acetone near any RX hull damage.

Finally back to the semi ludicrous test after a multi-week pause. (Hey, I got busy with other things)

I band saw cut each test piece of Royalex in half at the “damage” areas at the Vynabond, contact cement and acetone puddles.

P5150007 by Mike McCrea, on Flickr

Initial observations:

The lifted vinyl skin on the acetone soaked pieces became very brittle. Snappably brittle.

The acetone completely ate or dissolved the ABS layer. The thinner ABS layer below the inside vinyl skin simply vanished, the thicker ABS layer below the outside vinyl skin turned to goo.

And even where not eaten/dissolved the ABS separated it from the foam core, leaving voids and crevices. Even through the foam core to the side where the vinyl skin was not lifted

P5150009 by Mike McCrea, on Flickr

In that regard the pieces of Royalex pickled in acetone was a revealing test.

The contact cement and Vynabond puddled over damaged vinyl showed much the same, the trapped solvents ate the ABS layer below the burred/chiseled vinyl skin damage.

The foam core on all test pieces is more difficult to judge. The test pieces were all some ancient 20-30 year old Royalex, and the foam cores had decades to firm up/harden.

Even so, both the Vynabond and contact cement solvents produced similar action. Whacking the test piece at the solvent-trapped areas and at the unaffected edges with a ball peen hammer showed a couple differences in contact cement/Vynabond areas and un-adhesived areas of the Royalex.

The intact vinyl skin at the solvent areas is noticeably more brittle than at the distant un-solvented edges. The foam core, when ball peen smashed, stays smashed, the outer edges still have some residual spring-back memory.

I posit a theory about Royalex solvent damage; factory fresh or newer RX canoes may be more susceptible to solvent damage. I know from experience that it takes a couple years for the foam core to fully harden.

We have an RX Wenonah Wilderness that arrived day’s old from the factory, a canoe that was immediately put into use on multiple trips, tied to roof racks with ropes and trucker’s hitch belly lines. The belly line hitches left dents where pressed against in the still-soft Royalex. A series of dents from where we tied it on the roof racks on different vehicles with slightly different spacing. The foam core has since hardened, and rope hitches no longer leave dents, but those original dimples are still visible 10 years later.

That age hardening/curing may be the same for the vinyl skin, and even the ABS layers. Which would help explain why RX manufacturers are familiar with new canoe owner’s sloppily applied adhesive solvent complaints.

As soon as someone sends me factory fresh pieces of Royalex or T-Formex I will repeat that experiment ;-)