Page 1 of 2

A teardrop without any aluminium.

PostPosted: Mon Oct 15, 2018 11:54 am
by MikeG2
I'm a woodworker. My first instinct with any detail is to make it in timber. The teardrop I am planning for next February/ March is going to be distinctly "woody", with inspiration taken from some of the classic motorboats of the 50's, or maybe cedar-strip canoes of today, and I don't really want to see anything other than wood on its body. I'm even planning on making wooden mudguards (I can't remember what you guys calls those in America). I've sketched out a few details, and I can't see any great difficulty with this approach, although the door opening still needs a little thought. So I was wondering if anyone else here had built their teardrop without any aluminium profiles, and if you did, do you have any sketches of the details that you might like to share?

Re: A teardrop without any aluminium.

PostPosted: Mon Oct 15, 2018 1:45 pm
by Aguyfromohio
We built one with a wooden exterior. We used marine plywood, species Meranti, for the panels. It's certainly not cheap, $67 per sheet for 1/4 inch (6mm), but being exposed to the rain and weather we wanted the fully waterproof material. Our basic construction technique was plywood-foam-plywood, (glue laminated foam sandwich panel), so the sheets meet as a plain butt joint. To cover the ugly glue line and give us an extra barrier against water getting into those seams we glued and screwed oak battens. We put polyurethane on the whole thing, battens and panels.

Image

Re: A teardrop without any aluminium.

PostPosted: Mon Oct 15, 2018 2:01 pm
by MikeG2
And the trim at junctions like sides-to-top, or the hole for the door? What did you do there?

Re: A teardrop without any aluminium.

PostPosted: Mon Oct 15, 2018 2:18 pm
by steve cowan
Image

Image

The doors and window are trimmed with wood.The top molding at wall/roof is painted pvc trim.

Re: A teardrop without any aluminium.

PostPosted: Mon Oct 15, 2018 2:22 pm
by MikeG2
Ooooh, I like the wire wheels. That was the very first thing I decided on when I started designing mine.

Re: A teardrop without any aluminium.

PostPosted: Mon Oct 15, 2018 2:28 pm
by Aguyfromohio
MikeG2 wrote:And the trim at junctions like sides-to-top, or the hole for the door? What did you do there?


We used aluminum of two types that wrap around the corners. One intended as trim for a teardrop, plus some plain 1/2 inch aluminum angle. We use this profile from this vendor https://www.teardroptrailerparts.com/hi ... -trim.html

Image
We used that for the top of wall from the door to the tail , mainly because the 1.125 x 12 inch worked perfectly for our needs. At the curved nose and around the door we used 1/2 inch x 1/2 inch by .060 thick aluminum angle from Home Depot.

Re: A teardrop without any aluminium.

PostPosted: Mon Oct 15, 2018 2:44 pm
by MikeG2
Aguyfromohio wrote:.....We used aluminum of two types that wrap around the corners........


OK, thanks for that. I'm aiming to avoid any aluminium at all on the outside of the teardrop. Just the aesthetic I'm going for.

Re: A teardrop without any aluminium.

PostPosted: Mon Oct 15, 2018 6:28 pm
by Wolfgang92025
Mike,

I love wood. :thumbsup: :D
That being said, it does have some disadvantages.
Major one is water/moisture for a trailer with only wood on the outside.
Biggest challenge would be to keep it water tight and have the exterior finish last any length of time.
I have to re-finish my exterior every 2-3 years, and its parked in the garage when not in use.
I knew that going in, build still takes a chunk of time very time I have o redo it.

Re: A teardrop without any aluminium.

PostPosted: Mon Oct 15, 2018 9:27 pm
by Aguyfromohio
MikeG2 wrote:
Aguyfromohio wrote:.....We used aluminum of two types that wrap around the corners........


OK, thanks for that. I'm aiming to avoid any aluminium at all on the outside of the teardrop. Just the aesthetic I'm going for.

Sorry, my mistake. Reading your first post again I see that now.

The people who build wooden boats often use a layer of glass fiber cloth with epoxy resin as a top coat, the glass cloth becomes truly invisible. If you use that on the whole teardrop the corner treatment becomes less important -the corners end up with a strong mechanical reinforcement from the fiberglass plus a durable waterproof barrier. You could miter the edges or add a veneer for trim, whatever looks good, then glass it all over.

Here's a 4 minute video of a wooden canoe getting this clear fiberglass finish https://www.youtube.com/watch?v=hTTNvc4dYZY

Re: A teardrop without any aluminium.

PostPosted: Mon Oct 15, 2018 10:36 pm
by rkanz
I covered the top of mine with 4 ounce glass cloth and West System epoxy. I used a 1/2” round over bit on the corner - the cloth wraps over the edge. Sides are marine ply sealed with epoxy and 4 coats of varnish. The top is coated with marine paint. Will never leak and is very durable.

Image


Sent from my iPhone using Tapatalk

Re: A teardrop without any aluminium.

PostPosted: Tue Oct 16, 2018 1:24 am
by MikeG2
rkanz wrote:I covered the top of mine with 4 ounce glass cloth and West System epoxy. I used a 1/2” round over bit on the corner - the cloth wraps over the edge. Sides are marine ply sealed with epoxy and 4 coats of varnish. The top is coated with marine paint. Will never leak and is very durable...........


Wow, you were lucky with that stunning grain pattern in the ply. It looks great. I love the excellent kerf with the galley lid and around the door! I'd love to see close-up photos of those edges, with the door/ lid open, if you've got them.

Wolfgang92025 wrote:.....I love wood. :thumbsup: :D
That being said, it does have some disadvantages.
Major one is water/moisture for a trailer with only wood on the outside.
Biggest challenge would be to keep it water tight and have the exterior finish last any length of time.
I have to re-finish my exterior every 2-3 years, and its parked in the garage when not in use.
I knew that going in, build still takes a chunk of time very time I have o redo it.


Indeed. What have you finished yours with? None of the normal woodworking finishes would last long exposed to the weather. Obviously waxes and oils (including hardwax oils) aren't suitable, polyurethane varnish doesn't cope well with wood movement so would de-laminate and is very difficult to re-coat effectively, and lacquer............well.........I have taken to using water-based lacquer quite a lot lately. I might just put a few coats on an offcut and leave it outside for 6 or 9 months, just to see.

Aguyfromohio wrote:.........The people who build wooden boats often use a layer of glass fiber cloth with epoxy resin as a top coat, the glass cloth becomes truly invisible. If you use that on the whole teardrop the corner treatment becomes less important -the corners end up with a strong mechanical reinforcement from the fiberglass plus a durable waterproof barrier. You could miter the edges or add a veneer for trim, whatever looks good, then glass it all over.

Here's a 4 minute video of a wooden canoe getting this clear fiberglass finish https://www.youtube.com/watch?v=hTTNvc4dYZY


That's precisely what I was planning to do (and I've been following Adam's canoe build for a while). In fact, the look of that canoe is something like the look I am planning on for my first teardrop (somewhat like Juneaudave's). I'm also thinking about the deck of this boat. The big thing I need to find out is whether I can fibreglass the side panels separately on the flat, prior to constructing the 3D body. How well can you hide the join if you join new fibreglass to old?

Re: A teardrop without any aluminium.

PostPosted: Tue Oct 16, 2018 10:51 am
by swoody126
Mike, your concept is fully doable using MARINE PLYWOOD, EPOXY & GLASS CLOTH

the wood grain shows beautifully thru the epoxied glass giving it a varnished look when you coat the epoxy w/ several coats of good marine varnish

epoxy and the sun are not friends as a general rule and the epoxy does require a UV barrier (several coats of a good marine varnish works well)

the edge grain of good marine plywood finishes quite well when epoxy coated first

here is a pic of 3 layers of marine okume plywood laminated together epoxy coated and varnished

fullsizeoutput_f79.jpeg
edge grain epoxied & varnished
fullsizeoutput_f79.jpeg (513.47 KiB) Viewed 1609 times


the 1 little hiccup in the pic was repaired and you would have had to have it pointed out to find it

i doubt that if i had not brought it to your attention the fact that this is 3 pieces wouldn't have occurred to you

if you use care with your build the edgegrain on good BS1088 marine plywood(species of your choice) will IMHO enhance your work

KEEP US POSTED

sw

Re: A teardrop without any aluminium.

PostPosted: Tue Oct 16, 2018 11:33 am
by MikeG2
Thanks for that sw. I once made an end-grain laminated ply table top, so I know how beautiful it can look (and I also know how frustrating it can be to find voids in the exact wrong place in your strips of expensive ply).

I guess it is the woodworker in me that is rather frightened of exposed endgrain. I have only ever made one thing in fibreglass, and have never coated it over timber, so I guess I probably discount it, and think of it just as a woodfinish. I must adjust my thinking. The thing is, with my construction (as it is at the moment), I'll have only a layer of 3mm (1/8") ply over the outside of my insulation, under my 3 or 4 mm of cedar veneering. 3mm ply exposed end-grain isn't going to look good in any circumstance, so I'll just have to design that away.

By the way, instead of varnishing the completed shell (I have an active dislike of varnish after a few failures over the years), I'll probably take it to a car-body repair shop and get them to spray it up with a few clear coats of their shiny stuff. I have a friend of a friend.....

Any thoughts on my idea of fibreglassing the flat side panels on the bench, prior to constructing the teardrop in 3D?

Re: A teardrop without any aluminium.

PostPosted: Tue Oct 16, 2018 1:43 pm
by swoody126
laying glass on a horizontal surface is easy peasy

coat the wood w/ epoxy and allow it to cure

once cured sand the epoxy

lay the cloth out over the entire surface and w/ your hands(in NITRILE gloves) smooth all the wrinkles out

always(when possible) begin coating by pouring the pox in the center of your work and w/ a plastic auto body shop putty spreader squeegie the pox out toward the edges

bondo spreader.jpeg
bondo spreader.jpeg (4.13 KiB) Viewed 1589 times


the first coat on the glass should make the silverish fibers go clear(the silver appearance is only the light reflecting off the fine fibers)

squeegie the cloth down to the wood leaving a weave pattern that you can see and feel butt the cloth will be clear

here is a pic of an old home made oar the grandkids broke and i have glassed over the repair w/ the 1st coat of epoxy

fullsizeoutput_f7b.jpeg
fullsizeoutput_f7b.jpeg (579.92 KiB) Viewed 1589 times


at this point simply dragging the spreader over the weave will feel like it is dryish

allow this coat to cure slightly (just barely tacky) and apply a second coat again beginning in the middle

this is called HOT COATING and the result is one thicker application instead of several coats that are layered

repete this step until you have a totally slick surface

if you allow these last coats to cure completely it will be necessary to sand between coats

when the pox is almost finger nail scratch cured you can cut any excess cloth away w/ a sharp pair of cheap scissors being careful not to lift the glass cloth away from the wood

once fully cured a rasp will knock the excess cloth off easily

one caution before i sign off is to be sure to use 2 PART EPOXY not FIBERGLASS RESIN which is a polyester product and is hardened w/ drops of catalyst(usually an MEK family member)

ALWAYS WORK IN A WELL VENTILATED AREA AND WEAR BREATHING PROTECTION AND NITRILE GLOVES(many of these chemicals will melt latex and you don't want this stuff on your skin!)

BONNE CHANCE

sw

Re: A teardrop without any aluminium.

PostPosted: Tue Oct 16, 2018 4:19 pm
by MikeG2
swoody126 wrote:..........one caution before i sign off is to be sure to use 2 PART EPOXY not FIBERGLASS RESIN which is a polyester product and is hardened w/ drops of catalyst(usually an MEK family member).......


These few words may have saved me from some sort of woodworking catastrophe. I had always assumed that these were the same thing. That 2 part epoxy was fibreglass resin.

Huge thanks.

Having built up the layers on the flat sides, will overlapping the fibreglass from the top onto the sides produce an invisible join, or do I have to treat this differently?