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Old Town Pack Refurb Advice

Hi,

Long-time paddler, new member here. I just picked up a Pack for $50. In short, it was not treated nicely. I'm looking forward to a winter restoration project.

The canoe is worn down to the foam core at either end of the keel. The center seems to have oil canned inward (if that makes sense) and there is a terrible attempt at a patch job in the center hull. The center hull seems a little wobbly.





I heard that there is an epoxy that works with Royalex.

Does anyone have recommendations on material I can use to repair it? I was thinking of adding skid plates, a keel guard and repatching/reinforcing the center with glass, adding some strength.

I'm not that worried about added weight or looks. Just need it to be seaworthy.

Thanks!!!!

Joe

Comments

  • edited January 31

    Well, first off the hull is "hogged" as in "hog backed". Having a hull that is hogged is not desirable, but sometimes a moderate degree of hog back does not impair paddling function as badly as one might expect.

    Second, you have erosion through the green vinyl outer layer and through the outer ABS solid stratum of the Royalex into the "foam core" at both stems.

    The "repair job", which is truly grotesque, looks as if it consisted of someone slapping a rectangular patch of fabric, probably fiberglass, onto the interior and exterior of the hull with God knows what type of resin.

    G Flex epoxy, made by West Systems, is formulated to provide better bonding strength to plastics, including ABS. More traditional types of epoxy have been used to repair Royalex boats with variable results, but these do not provide as strong a bond as G Flex does. I have seen repairs to Royalex boats done with conventional epoxy where a patch looked reasonably good sometimes for years, and then the whole thing flaked off one day down the road.

    Amateur hack repair jobs almost always make a proper repair at least twice as difficult as it otherwise would be. The good news here might be that the repair job is so crappy and the bond so weak that the applied resin and fabric might come off easier than one might expect. If I am interpreting the photo of the interior correctly, it looks as if some of the fabric on one side of the patch has already come loose and chipped off. I would try getting under that edge with a paint scraper or putty knife and see if you can chip off the remainder of the fabric and resin. Anything that does not easily come off could be sanded off given time and patience.

    That will likely leave you with areas on the inside and outside either completely or partially denuded of the green vinyl layer. These areas could later be covered with fiberglass patches properly applied. If you go this route, I would use some wooden spacer sticks to "jack out" the hogged hull section before applying the patches, This can be done by clamping a 2x4 to the gunwales transversely just forward and aft of the area you need to patch. Then cut some sticks of just the right length to act as vertical risers to jam between the 2x4s and the hull bottom to apply outward pressure and maintain it while the epoxy cures.

    The damaged stems can be repaired by filling in and covering all of the areas of exposed foam core with G Flex epoxy thickened a bit with colloidal silica powder. Then after covering the core and "replacing" the lost outer solid stratum of ABS, sand the cured epoxy flush and fair and cover the area of damage with a longitudinal fiberglass patch.

    Dealing with the hogged hull is trickier. Most Old Town Pack canoes are paddled sitting of a fairly low seat. If this is your plan, and you do not need room beneath the seat for your feet to be able to paddle sitting, you may be able to fashion some blocks of minicell foam to place between the bottom of the seat frame and the hull bottom to help push it back out into shape. Or you might place a thwart just behind the seat with a foam block between the bottom of the thwart and the hull bottom.

    There have been quite a few threads on this forum detailing repair of Royalex boats, Here is one you might choose to review:

    http://forums.paddling.com/discussion/2936942/skid-plate-prep-work-on-damaged-bow

    Here is a public album detailing the repair of a Royalex canoe that had been pinned and had sustained significant damage requiring interior and exterior patches. If you go through the photos individually, you will find a caption describing what is being done:

    http://www.flickr.com/photos/42020723@N02/albums/72157657942924708

    Good luck.

  • Pblanc,

    Thanks! I've read some of the posts that deal with these types of repairs. Your advice confirms and consolidate s, in one spot, what I have already seen in few threads.

    I will pick up 32oz of g-flex, some colloidal silica, 6oz fiberblass fabric, and some j-weld plastic putty. (The putty is just to smooth over a couple interior dents)

    Thanks specifically for the advice on dealing with hogging. That was a first and I will def try correct with 2*4 and risers when I apply the glass. Actually this is the thing that worries me the most.

    And yes, the "patches" on both sides were done so poorly that they came off with a little coaxing from a chisel. Now at the tar-like resin with a putty knife.

    Thanks again. This was really helpful. I will post some pics when I am finished with this little guy.

    Would you recommend anything to remove oxidation from aluminum gunwals? Is this even possible or advisable?

    Thanks

    Joe

  • edited February 1

    Thought Pack gunwales were vinyl covered, but if bare aluminum I suppose you could sand/grind them? The Pack is a fun little boat...so easy to toss around and great for getting in small places. Had a buddy years ago that stuffed his with a big front airbag and played the middle Yough class 2 stuff.

  • Stevet,

    Thanks. I just assumed they were aluminum because they had oxidized. But I guess vinyl does that too.

    Maybe a vinyl cleaner then? I'd like to remove the chaulky oxidation.

    Ya, I cant wait to take this little guy to some backcounty small streams.

    Joe

  • Have you ever paddled over a rock or log and watched the bottom of the boat flex as the boat passes over the object? If you fix the bottom to force it unhogged, the bottom won’t flex and the boat will develop wear spots beneath the structures you install to force the bottom downward.

    I recommend ignoring the hogging. It is difficult to do anything about it, and I don’t think the performance of the boat is much affected by the hogging.

    ~~Chip

  • edited February 1

    There were many Royalex whitewater canoes that had a long, foam pedestal, or even a rigid rotomolded polyethylene saddle, on the hull floor tightly pinned beneath two thwarts at the front and back. Yes, occasionally some of these would develop cracks at the stress riser formed at the front edge of the saddle, but usually only after going over quite a few rocky ledge/drops over years of use. Here are a couple of examples:

    For the type of use that the typical pack canoe sees, I do not think foam risers of that size will cause any problems.

    But it may be that the performance of the canoe will be satisfactory without addressing the hogging issue.

  • edited February 1

    Thanks, folks. This is useful, as my only experience refurbishing a canoe was repairing the hull of a Swift Kipawa in "Expedition Kevlar" with a hole the size and shape of a foot-long sub sandwich. Working with the gelcoat was the toughest part. It took months. Royalex is a mystery to me.

  • Photos Stage 2. Prepping and cleaning. Next the expoxy and glass.

  • That looks like a really good job so far. When you lay cloth over the exterior of the hull over that raised keel area, make sure the cloth lays down well against the ABS without voids. You may have to keep coming back to the job over an hour or two as the epoxy cures and becomes tacky to keep pressing it down on the hull with your squeege. When it becomes tacky enough, it will stick. On the interior, I might be tempted to fill in, or partially fill in the depression along the keel line to allow your cloth to lay down more smoothly, although that might not be necessary.

  • I never thought of going back to make sure the glass is behaving. Thanks for the tip. I planed to fill those areas on the inside with thickened epoxy to get the whole area as smooth as possible before I lay the cloth down. I don't want to make it too "rigid", so I plan on going easy. I plan on 3 layers of 6 oz cloth on the outside and 2 on the inside.

  • edited February 7

    As you wet out cloth trying to conform to a sharp angle, as the fibers soak up the resin they have a tendency to want to straiten out, which lifts the cloth off creating a void which will be a weak spot. If you keep working the cloth down as it becomes tacky, at some point it will adhere. If you are applying multiple layers of cloth and apply each new layer while the epoxy of the preceding layer is still "green" you will usually be fine. If for some reason a few days go by before adding a new lamina, wash the repair area to remove any possible amine blush which can interfere with the cure of freshly applied epoxy. In general, repairs will be stronger if all layers on one side are applied while the epoxy of the preceding layer is green as that will result in a "chemical bond" rather than just a mechanical bond.

    When applying multiple layers, cut out your fabric so that the lines of the weft and warp of the woven cloth do not align with each other. There are no anisotropic fabric lines in Royalex to consider so if you wish, you can lay down your first layer of cloth so the the fibers are aligned parallel and perpendicular to the keel line. But then for a two-layer repair, cut out your next piece of fabric on a 45 degree bias. That will place the fibers crossing each other a maximal number of times. For three layers cut the second patch with the fibers at about a 30 degree bias and the third at about a 60 degree bias, etc.

  • edited February 19


    Well, a frustrating, yet minor, setback. G-Flex epoxy is extremely thick and difficult to work with (compared to regular West System Epoxy or Polyester Resin). I mixed and laid it down per the instructions (on a thoroughly sanded, solvent-cleaned surface) and the finished result was a poor bond and brittle epoxy. Not my best work.

    It was probably too cold when I mixed the epoxy, making it too viscous to properly bond and impregnate the fiberglass.

    I will be removing the epoxy and glass and re-try with warmed epoxy and 5% acetone - to help viscosity. I think the trick with this stuff is to mix it in small batches, use it in very fine coats, and at the right temp.

    As an aside, a few drops of the mixed epoxy leaked on to concrete floor in the garage. Let me say that this stuff bonds EXTREMELY well to dirty concrete. Taking the drops off also removed some of the floor!!!. ![]

    PS - I mixed a batch with some colloidal silica to thicken, applied that to the keel, sanded cleaned, then layed the glass with un-thicken G-Flex. Going to skip the first step next time, or try some plastic weld.

    (https://forums.paddling.com/uploads/editor/b5/6ydkqk96bgfl.jpg "")

    Will report back.

  • A few thoughts.

    As for surface preparation, if I am applying epoxy to a Royalex surface I will first sand the area with 100-120 grit sandpaper, then thoroughly wash the area with warm water with some dishwashing detergent using a scrub brush. If you have exposed foam core, you want to keep that fairly dry because if water gets into it it takes some time to dry out. After thoroughly rinsing the area, I go over it denatured alcohol. Then after that has all evaporated, I wipe it down with an acetone rag.

    You have to be a little careful using acetone on Royalex because it will disolve ABS. Don't get it on any of the foam core as that thin material will dissolve quickly. Don't allow any liquid acetone to puddle on the surface, and don't leave any acetone rag in contact with the hull, even if it feels pretty dry. But wiping solid ABS with acetone is OK because it will flash off before it does any damage.

    G Flex is more viscous than conventional epoxy even when unthickened. I try not to use it unless the ambient temperature is 60 degrees F or more. You can carefully warm the surface you are applying the epoxy to with a heat gun and you can also warm the mixed epoxy before application and waft a heat gun over it after application if you are careful not to overheat it.

    I use thickened G Flex epoxy to fill and bond cracks, and to fill in voids or markedly uneven surfaces to which I am applying cloth. If I think the outer solid stratum of the ABS of Royalex has been markedly thinned out, I will try to build that back to original thickness with thickened G Flex. But I mix it up in small batches which is easy to do because you can mix it even in very small batches in a 1:1 ratio by volume by eye. When filling in voids or cracks I expect to use multiple applications and I apply it in thin layers. It is OK to apply more epoxy as soon as the preceding application has cured enough to not sag or run so you can usually get quite a bit done in a few hours time on a reasonably warm day.

    Since you obviously had a bonding issue, next time I would probably go ahead and pre-treat the surface by flame oxidation with a hand-held propane torch. The instructions that come with G Flex describe this process well. You want to keep the flame moving along to avoid overheating the Royalex which can deform the foam core. And if you have prepared the surface with alcohol or acetone, make sure that has all flashed off completely before using the torch or you will have a canoe flambe. Also, I would not use a torch on any exposed foam core as that melts very quickly. All the little "cells" within the foam core should provide very good anchor points for the epoxy. I have used G Flex on ABS boats without pre-oxidation and gotten good results, but West Systems says that this does enhance the bond strength in there tests. Try to apply your epoxy within 30 minutes of flame oxidation. If you are applying cloth to an area to which you have already bonded G Flex, you don't need to flame the cured epoxy, only any exposed ABS.

    After filling in any voids, cracks, and exposed foam core and sanding the area smooth, I would not apply any additional thickened epoxy before laying on cloth. I do apply a thin layer of unthickened epoxy to the hull before laying on fabric as I think this helps wet out the cloth. Any time you are applying more epoxy over cured epoxy, you need to wash the cured epoxy with soap and water to remove any potential amine blush which can interfere with the cure of freshly-applied epoxy.

    Finally, it looks as if you are using fiberglass roving. I would strongly recommend that you use plain weave fiberglass cloth, no heavier than 6 ounce/square yard. Roving is considerably harder to wet out than plain weave fiberglass.

  • Thanks, pblanc! Much, much, appreciated. I plan to pay closer attention to prepping the area, thinning the epoxy, using smaller batches/applications, and laying down a better cloth. Is this does't work then it's bondo putty, polyester resin and spray paint.

  • Pblanc,

    I'm getting ready to revisit this project now that the weather is improving. Does the removal of the amine blush on cured epoxy need to be done right before adding additional layers? Or can I remove it a week before applying the next coat? I don't have much free time these days, so have to do projects like this wherever I have an hour or so.

    Thanks,

    Joe

  • Epoxy cure is a chemical reaction and it is my understanding that the process can take weeks to complete, even though the great majority of the process is finished within a day or two. So in theory, at least, excess amines could continue to accumulate on the surface for a fair bit of time.

    It doesn't take much to remove the amine blush. Just use some warm water with a bit of dishwashing detergent in it and lightly scrub the surface. Then rinse and towel dry it. I usually also wipe it with denatured alcohol and allow that to fully evaporate which will get rid of any residual water moisture. The process could be completed within a quarter hour or so.

    If you apply another coat of epoxy over one that is still green, you do not need to remove amine blush. You can certainly apply multiple coats of epoxy in the same day without washing, and usually the next morning is also OK.

  • edited August 2

    Pblanc,

    Finished the project thanks to your advice. Had it out twice on the Deleware and the repairs seem really solid. I think the combination of mixing large batches in colder weather, with the wrong type of glass, and possibly animes, was the issue the first time.

    Won't win any beauty contests, but that was never the point .

    Thanks again!

    Ps- Just picked up a bell Northstar that will need some gel coat work and new wooden gunwales. I will definately be hitting up the forum again for some advice and will be sure to pass along my knowledge.

  • Looks good.

    Get some spray paint that more or less matches the faded color of the boat. Mask off the areas of your repair and paint the patches to protect the epoxy from ultraviolet light degradation. The paint will tend to get scratched off, of course. But it is a pretty simple matter to remask the areas and give them a quick spray to touch them up every so often.

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