Within 72 hours
In addition ta what G2D said - yer kin’ generally put another layer of epoxy over a previous layer within 72 hours without having ta wash off de amine blush - which be a waxy layer formed on de surface from de curing process of epoxy). This may not always be de case wit different hardeners, though. Some form de blush, some don’t. After 72 hours ya gots ta remove de blush or de next coating won’t stick.
Fat Elmo
A few points
The layer directly underneath the vinyl isn’t the core, it’s hard ABS sheeting that’s usually either black or green. The core is a white-ish foam.
Personally, I don’t see why you’d remove more vinyl, let sleeping dogs lie? Sounds like you have similar wear to my boat, except that I’ve made it through to the actual foam core in a spot.
Phreon
I’ve been asking for data on this.
I have removed the vinyl over-layer when doing end repairs, but I honestly do not know if it is necessary. My materials “instinct” is that the stiffness/flexibility of the ABS is closer to that of the epoxy than is that of vinyl.
I could gather some data myself. The bottom of my Royalex Mad River Synergy is starting to wear through. I could put on a relatively large S-glass patch over the remaining vinyl and see if the glass and epoxy tends to delaminate from the vinyl when the boat goes over logs, rocks, etc. If there is very little or no delamination, that would indicate very good adherence of West epoxy to vinyl.
the layer in question is gray
and it is soft and spongy to the touch. noly a very thin layer of vinyl over it.
No, but they are a reputable supplier.
As for quantities, West comes in approximately quart cans with a little can of hardener. And you get the pumps for their 5:1 mixing ratio. I think I paid about 60 bucks for all that, but that was several years ago. However, you can do a tremendous number of repairs and projects, and the stuff lasts several years even if you leave the pumps in the cans. (I do.) With time, the resin thickens just slightly (according to West) but the hardener thickens more and turns a dark reddish color. It still patches effectively, if you can deal with the dark red resin rather than the usual light honey color. I use old West epoxy for furniture repair of red woods like mahogany and cherry.
Because I’m neurotic. I would not wait
more than a couple of hours to add another layer without sanding and cleaning. West seems to give the same advice.
E-Glass, S-Glass or Dynel?
For maximum flexibility, impact and wear resistance?
Considering I’m repairing abrasion and not structural damage in a very stiff part of the boat, I figure greater impact and wear resistance is a priority over ultimate strength.
Thanks,
Phreon
link to thread on cboats re melting ABS
http://www.cboats.net/cforum/viewtopic.php?t=5474&sid=fdb575382db22c06ee1de37ab822d327Heidi
I have some Raka S glass and resin
I used it to cover a lee board for a sailing canoe. The end hits some rocks but it doesn’t see near the abuse my boats do.
Anyway the resin was easy to to use and lee board with one layer of 4 oz glass has held up well.
Tommy
Follow-Up
I really don’t wish to necro-post an old thread, but I found it in a google search while considering advice for my latest boat and thought I’d include a follow up for posterity. I must be slightly senile, finding old posts about a question I’ve already asked.
I sanded areas I planned to fill in and cleaned them sparingly with MEK. I built up the heavy wear and filled in a few small gouges with plain ol’ JB Weld (Industro Weld, which is the same thing in a bigger tube). The bow and stern got custom skid plates made from a Xynole (somewhat like Dynel) patch layed up with Raka epoxy filled with fumed silica for thickness and ultimate hardness and graphite for self lubrication and semi-UV protection.
The result was ugly black skid plates, but they were very smooth/flush to the hull and four years later are still going strong after many impacts and abrasions. Thanks to the graphite, they’re distinctly “ungrabby” as well, slipping over rocks I clearly meant to hit just as well, if not better than the surrounding RX.
The above layup flexes with the hull well enough; I’ve never had a chip, crack or peel away, unlike many a kevlar skid plate.
The unprotected JB Weld patches where I filled a few deep gouges are also still going strong. I think the key here is to really rough up and clean the surface before applying. I’ve detected no difference in adhesion between JB weld and the underlying ABS or outer vinyl layer. It’s also worth mentioning one can customize JB Weld’s ultimate harness/flexibility by experimenting with the hardener/filler ratio.
We’ll see how well JB Weld sticks to roughed up R-84 on my “new” Dagger Rival. I wasn’t so worried about abrasion so much as protecting the exposed underlying layer from UV in a few small spots I manged to take divots out of the hull on the middle Tellico.
Cheers,
Phreon