Royalex repair - Perception HD-1

[sbridge]

Question: A section of the outermost layer of a Royalex canoe has become detached from the layers below.

Should I

a) cut open the outside layer, fill the void and royalex repair resin, and then put a Kevlar skid plate over the whole area,

b) leave the still intact and watertight - but detached - outer layer intact and simply put a Kevlar skid plate over the whole area?

What a great web-site. I was looking for info on Royalex boat repair and found you all. I’m an old-timer who started out as a raft guide (in the ancient past) and then moved into OC-1 and C-1. I’m currently down to four boats: two open and two closed. (Maybe I should try to sell one here.)

The boat I want to fix is a Perception HD-1. Any good memories out there? It was old but pristine when I bought it as used demo ten years ago. Now it needs help. I’m planning on using 3 royalex skid plate kits right down the middle from bow to stern (or maybe just the front 2/3 or ¾ of the boat due to its rocker) – and royalex repair resin and/or repair kits to fix a couple of worn spots. Then there’s the sort of “bubbled up” place on the bottom of the boat where the outer layer, colored layer has detached from the layers below.

Another question: Any thoughts on a boat that is similar to this old classic? (I know it won’t last forever.) I’m using it for week plus wilderness camping, whitewater trips, so some volume is needed.

[sbroam]

I'm not an expert on this and others will chime in quickly I am sure, but here are a few thoughts :

1. the typical kevlar skid plate is not flexible, but rather brittle and heavy - you may want to try other repair methods. That said, I did similar to my first whitewater boat - I took took skid plate kits and starting at the stern went as far forward as I could going right down the middle. A year later when I sold it, it still looked good

2. I am fixing some canoes that have a similar delamination issue. At the "Ain't Louie Fest" I asked Mark Scriver what he would do and he suggested drilling some holes in the outer layer, every 2-3", and inject some resin into the void. This shoul tie the inner and outer layers back together.

3. As for reinforcing/repairing the outer layer, I'm using ABS putty (search for description) to fill in gouges/divots. I'm cementing sheets of ABS (about 1/16" thick) to cover the larger areas. Over this I am putting 1-2 coats of Krylon Fusion paint - not just for asthetics but to protect the ABS from the UVs.

Good luck with your boat!

Scott

[Jim Michaud]

Scott has some good points. First off, scrap the Kevlar skip plate idea. Like Scott said, it's too brittle. Every time that I've used Kevlar felt it ended up breaking apart in the stern.

Drilling holes in the bottom of the boat is a good idea. I would strongly suggest Gorilla glue instead of resin. Gorilla glue expands when it dries so it will do a better job of filling in the delaminated areas. I cover the holes with plastic wrap topped with sand bags and a cinder block while the glue dries.

Scott's idea of gluing sheets of ABS sheets seems like a lot of work and the sheets may not conform perfectly to the boat's curvature (just guessing, haven't tried it). I just sand the vinyl off of the bad areas then paint the area with several coats of ABS that has been melted with MEK or acetone.

Jim

[sbridge]

Thanks for the advice. You guys have already saved me lots of money on materials. Kevlar is expensive. I think I’ll try the drill and fill technique. And thanks for the sandbag tip! The delaminated spot is, of course, right in the very center of the boat – where the most abuse occurs. Would several coats of ABS melted with MEK or acetone be sufficient for this high scrape zone? (If you remember, has there been a previous post here about how to make and mix that?)

Thanks again,

You guys are awesome,

- Steve

[mshelton]

ADHESIVE!!!

[sbroam]

Scott's idea of gluing sheets of ABS sheets seems like a lot of work and the sheets may not conform perfectly to the boat's curvature (just guessing, haven't tried it). I just sand the vinyl off of the bad areas then paint the area with several coats of ABS that has been melted with MEK or acetone.

I have not had much luck getting sheets to conform to curves in the hull - at least not where there are curves in more than one direction - the best example of that is at the chine (on a hard chined boat). Some have suggested heat (gun or oven) or solvents to soften the plastic. I've tried the former with little success and never the latter.

However, to cover a large, flattish area, I think the sheets work great. I patched the worn area under the seat of one of my old OC-1s and got another couple of years out of it.

The trick is finding the sheets and cement. If you have a plastics supply house in town they might stock it or can order it for you.

I'm definitely a convert to the ABS putty approach, but I think covering a large area could get messy, but that might just be me.

What I have been doing to make the putty is taking small bits of ABS and putting them in a mason jar with some acetone. Everytime I walk by it, I git is a shake and usually by the next day it is in solution or approaching it. I give it a stir with a tongue depresser and add acetone til I get to a consistency somewhere between toothpaste and peanut butter. The thicker it is, the less work time you have. It is kind of like caulk in that it can be self leveling and it you touch it after it starts to skin over you bugger it up.

[knu2xs]

Having started my paddling career in an HD-1, I got rather good at repairing it. The foam core is thicker, as well as all other layers for that matter, than most any new boats out there. This explains the boat's heft as well. Your best bet is to split the thing open and fill it with an epoxy designed to have the same flex rate as royalex or ABS in this case. This epoxy (I think) is made by Mad River. By using this stuff, I managed to squeak almost two more hard seasons out of my boat during junior high and high school.

[ezwater]

My approach would be to try the drill-and-fill method, and/or to use S-glass or E-glass and West epoxy to stiffen the outside of the bubbled area. There are different schools of thought as to whether the vinyl should be scraped off the outer ABS layer, but epoxy may stick pretty well to the vinyl.

If the drill-and-fill works well enough, then perhaps only two good concentric layers (biggest layer first) might be needed on the outside.... surely no more than three.

I might feel anxious about using an expanding glue like Gorilla Glue, unless I had a way to forcefully hold the bubble down until the glue sets. I think I could inject epoxy for the same purpose, though it would work only if a relatively low volume were needed. But if epoxy is used, make very sure that the interior of the bubble is dry. Epoxy and moisture do not like one another.

Another possibility is to make thin slices in the bubble, perhaps in a cross pattern, to allow it to be forced flat as it is glued down. Then three layers of S-glass and epoxy would nail everything down and firm it up.

[Jim P]

On the ABS repairs - a few coats of the ABS putty if placed over a delaminated spot will crack pretty badly and quickly. The putty works well over a sound base. Some kind of reenfocement is needed. I'v ebeen testing a layered aproach with woven glass and ABS putty and so far it seems to solve a lot of problems. Only time will tell.

Putting expanding stuff into a delaminated spot can spread the delam area past the existing delam boundary into new frontiers. Had this problem with the very expensive 3M 3532 epoxy. Great suff sticks to ABS well and stays flexible - just beware when stuffing between layers. Have not used GG on a boat but if I recall it expands more than 3532.

[phreon]

FWIW, I had significant stem wear on an old Mohawk I purchased. I filled the area with plain old J.B. Weld knowing full well it'd probably crack if unprotected during a hard hit. In lieu of kevlar skid plates, I added grind pads made of Xynole cloth and RAKA epoxy resin. The first layer was plain resin w/the cloth and the two further layers of resin applied contained about 15% graphite powder with cabosil (silica) as a thickening agent. The skid plate areas still have a little give and have taken a few thwacks so far with barely visible scuff wear to show for it.. Scratched areas are actually slipperier than virgin epoxy.

You might consider replacing damaged core foam with Gorilla Glue. Not only does it foam out when it dries, it actually requires moisture to cure. It's somewhat flexible too.

Phreon