Need advice from Woody owners on the exterior finishing.

[kookenotes]

I began my first build the first week in August based on the BenRoy plans from the web site (Thank you Mike - they have been incredible) . I have been scouring the threads in this amazing web site, sort of non-stop, for the past two months trying to understand best practices, regrets and do-overs. My outside walls are cabinet grade 3/4" oak. My plan, based on a very large number of your posts, is to finish the outside with three coats of CPES applied over min-wax gel stain, and then followed by 5 or 6 coats of McClousky's "Mon-O-War" spar varnish. The roof and hatch will be covered with aluminum. Does this sound like it is a workable plan. My finished TD will always be housed in a climate controlled garage and let out to play only when I take it camping, which I hope will be at least monthly. Any thoughts or advice will be greatly appreciated. Thanks again to Mike and the whole group for all of the helpful posts. There is an amazing amount of innovation and residual knowledge on this web site. Bill

[len19070]

I built these 2 "Woodie's" the white one in 2003 and the green one in 2005 using the method your thinking of.



They held up ok but if I was to do it again I would use some kind of epoxy. I didn't use it on these 2 because at the time, I really didn't know anything about Epoxy's...I did know about Spar Varnish's.

Happy Trails

Len

[kookenotes]

Thanks for your response Len. Would you have used epoxy instead of the CPES or Spar Varnish or in addition to them? I'm a little uncertain about the sequence although I know the stain must be applied before the wood has any sealer. What epoxy would you use on the next one and at what stage would it be applied? Thanks for any help. Bill

[kookenotes]

By the way Len, those are two really great looking Tear Drops . How often do you have to re-varnish them?

[nevadatear]

Stain, then epoxy, then varnish. The epoxy protects the wood, the varnish protects the epoxy from uv breakdown. On a woody with a clear look, i believe epoxy is a better choice than CPS.

[Juneaudave]

Stain, then epoxy, then varnish. The epoxy protects the wood, the varnish protects the epoxy from uv breakdown. On a woody with a clear look, i believe epoxy is a better choice than CPS.

+1 If you decide to use something other than Min Wax Gel...be sure and check a epoxy over stain compatibility chart!

[kookenotes]

Thanks for the responses folks. I was looking for a viable substitute for the CPES and would far rather use the epoxy. I will do my research on the products available. I see that the West system products are compatible with the MinWax Gel stain and will probably lean in that direction. My build is really starting to take shape. The walls are up temporarily and all of the cabinetry is built and ready for the finishes. This has quickly become an obsession.... I need to figure out how to post some pictures of the progress. I really appreciate all the help and advice. What fun!!

[jonw]

I question why you feel the need to use both CPES and varnish. I'd simply use Spar Urethane over your stained or unstained wood (that's what I did on mine). Yes you will have to re-varnish it every several years but you will have to do that anyway to restore the UV protection for the CPES.

Also I recommend using a HVLP sprayer to apply the spar urethane. It does a great job of applying it evenly (no brush marks or thicker section overlaps) making it look like a professional job. It also uses very little material (urethane). Once you've masked the trailer you can leave it masked in between coats - masking an object as big as a trailer is relatively easy, and the whole process is a very efficient and easy way to go.

[kookenotes]

Hi Jon - Thanks for your reply and your thoughts on going straight to the spar varnish. I have gotten the impression that sealing with CPES was sort of the holy grail on this forum. I don't have a lot of confidence in my spraying abilities since my only experience is with rattle cans and somewhat unprofessional results. I have the sides of the TD on temporarily and my cabinets are all built and ready for installation but there is no sealer on the plywood edges yet and I am kind of stalled trying to figure out the next move . I want to stain the outside walls with Minwax gel stain because I have had great success with that product. I don't want to use any sealer that will interfere with the stain so I guess the stain should be next. If I stain it next can I then use the spar varnish (Planning to use McClusky's Man-o-War because of its reputation for staying flexible) to both seal and finish the outside. I understand that I will need to re-coat every couple of years. I have had very good results with brushing on Polyurothane finishes with good quality brushes so I feel I can brush on a good five or six coat finish. I welcome any thoughts or suggestions.

[Oldragbaggers]

Double posted.

[Oldragbaggers]

I personally would not be comfortable using only varnish. Varnish, exposed to moisture and UV, can and will at some point, start to flake up enough for water to get under it. Anyone who has ever owned a boat with a lot of exterior wood can confirm what I am saying. After a year or so you will start to see dark spots on your wood under the varnish where tiny hairline fissures have allowed water to get under the varnish and start to darken the wood. If we are talking about the hardwoods used on the exterior of a boat it's not that big a deal. You sand it down, revarnish and you're back in business for a couple of years (although most people sand and varnish yearly to prevent this from happening). If you're talking about plywood, especially if it isn't a good exterior grade of ply with waterproof glues, you could be talking about delamination.

A lot of people use CPES alone, others use epoxy resin alone, others use both, some lay up cloth. Me, I am certifiable and have used all of these, not all together, but different methods on different portions of the build. I would say that if your teardrop is going to be garaged or kept out of the elements, and if you plan to be diligent with the upkeep of your varnish and performing regular inspections for leaks, you probably can skip the epoxy sealer, but I should think the peace of mind would be well worth the extra step, and especially on the edges of the plywood which will absorb any water that finds its way there like a sponge. (Did you see the delamination on Mike Schneider's Baja Benroy.....YIKES!!!)

At the very least, if you decide to go with only varnish, I would apply a couple of coats of varnish that have been thinned so that it will soak deep into the wood and seal it as much as possible before applying the surface coats.

Just my 2 cents, and probably worth about that.

[kookenotes]

I appreciate the guidance. If I seal with the West System Epoxy before the spar varnish, can anyone give me an idea of the quantity needed and should I go with the fast or slow hardener? I would assume for a first time user (Newbie ) that the slow catalyst would be the best. If I get a gallon of the resin, do I need an equal quantity of hardener or is there a recommended ratio. I am looking at Amazon and they do not give much information on coverage. Thanks, Bill.

[Oldragbaggers]

I would make a couple of recommendations. First of all, whether you use slow or fast hardener has everything to do with the temperature you are working in. Slow hardener would be used in hot temps, fast hardener in cold temps. With some epoxy systems (Raka for example) you can mix slow and fast hardener to get a medium speed. Consult their manual for which to use in what temperatures and to allow for certain pot working times.

Please don't consider me the expert but I have had a lot of experience with West system (as a matter of fact that is the only epoxy I worked with for 25 years) and I would recommend Raka for this particular application for a couple of reasons.

First of all Raka has a non-blushing hardener (350). Cleaning blush off of epoxy is just a pain and in this day and age unnecessary. Not that it's hard, but why do it. I think West has a non-blushing hardener also but it is more expensive than Raka.

Raka is thinner and less viscous so it rolls on easier, absorbs better, and goes further. (Although if you are using it on a vertical surface you will need to be very careful to watch for runs and drips. So if at all possible, coat your walls laying flat.)

Raka dries very clear. West can tend to be a little hazy and have a bit of a yellow tinge to it sometimes. This is not a problem if you plan to paint or skin over it, but for a woody would be undesirable.

Raka is much cheaper. Their service is excellent, shipping prices quite reasonable, shipping is fast, and it just works well.

I used Raka for the first time ever building this teardrop and for layup and clear coating I will now use it exclusively. (For bonding I still use West, but mostly because I happen to have a good supply of it left over from boat projects and I know how it works with all the adhesive and fairing fillers, which I also have a good supply of.)

As far as the mix proportions, again it depends on the resin and hardnener. Even within the same brand, different hardeners may have different ratios. For Raka #127 resin and #350 hardener it is 2 parts resin to 1 part hardener by volume. You can either use measuring cups or they sell metering pumps you can stick right into the bottles. I was doing it by grams on a scale for awhile but I found out that wasn't really the accurate way to do it. Fortunately there is a margin of error of about 10% within which it will still perform to standard (according to Raka literature.)

I understand you are putting cloth on your roof. They have excellent prices on their cloth and it is good quality. It comes in 60" width also. The last time I ordered a piece for my hatch I ordered, and they charged me for, 2 yards. They sent at least 6 yards. They don't short change you by any means.

Other people may have other recommendations. I can only speak from experience about West and Raka.

Again....wishing you the best of luck with your build and looking forward to following your build journal.

[kookenotes]

Hi Becky - Thanks for the information on RAKA. I visited their web site but it was too late to get them today. I will call them on Monday and feel pretty sure that it's the way I will proceed. I have the outside stain in hand and was planning to use Minwax gel. I assume it will be compatible. I will check with them. If I start with the six quart kit, in your experience, will that cover the outside roof and sides on a 5 X 8 Benroy. I don't think I will be using cloth on the roof since I plan to skin it with aluminum. Also, with the viscosity of the Raka, how many coats do you recommend. Lots of questions , I don't mean to become a pest. BTW, I see you are in Maryland. I was born and grew up in Western Maryland close to Deep Creek Lake in Garret County. If you guys haven't made a trip up there with your TD you definitely should put it on your agenda. Thanks again and I hope to see you folks on a camp ground one of these days.

[Oldragbaggers]

As I said, it goes a long way. I don't know how many quarts you would need for just clear coating. I layed up cloth all the way around and that takes a lot more resin. Not sure how many coats either. I'm a fly by the seat of my pants visual kind of girl so I would probably put it on until it was shiny all over and the wood grain was completely filled in. With the edges I would make sure they were completely encapsulated. But that's not scientific, that's just how I would do it. Don't take my word as gospel. Like I said, I've got some experience but I'm no expert. (And most of my experience has been with fiberglass on fiberglass applications, not fiberglass on wood.) Maybe someone else who has more in-depth knowledge of epoxy and wood and/or only clear coated their teardrop could chime in for a better answer to this one.

I usually buy it 1/2 gallon resin and 1 quart bottle of hardener at a time. I've had to order a few times (3 I think), but like I said, I laid up a lot of cloth. I should think 6 quarts would be more than enough.