Wood Fenders

[Juneaudave]

I looked to buy some fenders for a Slumbercoach, the 11" wide ones, and it was $560 to get them to AK..kind of out of the question (shipping eats your lunch). So I guess I will build them, strip style, out of air dried sitka spruce available locally (nice wood, pretty cheap). I've done some bentwood work, so making them doesn't bother me.

But a couple of questions and I would take anyones opinion...

Would you (personally) line a set of wood fender with metal? Or would maybe some spray-on undercoating over fiberglass suffice and be preferable for the inside wheel wells...

I seem to recall some dimensioned drawings of profiles for several fenders...Does this ring a bell? or could a fella find the post?

Andrew..on the Slumbercoach pdf..you had a fender profile laid in...do you have the .dfx file for that sketch of the fenders? I'm needing dimensions to make up some jigs.

Thanks all...Juneaudave

[Micro469]

juneaudave, I'm thinking of building a Slumbercoach as well, and the cost of fenders is not in my budget. What I'm going to do is draw the tire circmferance and the use the fender shape from Grant and then cut out the shape from 3/4" plywood. Then I'll layer it to the thickness I need (11"?) and glue them together. Sand and coat with epoxy. I think the pattern of the edge ply would look cool. I wasn't going to share this, but what the hay, we are a kind of family no? 1/2 " back piece the shape of fender, 2" cutouts the depth of fender, 1/2 or 3/4 " face, routed out to round corner, covered with epoxy to protect.
Would look good, you could use this design if you want. It will work.

[48Rob]

Dave wrote;

Would you (personally) line a set of wood fender with metal? Or would maybe some spray-on undercoating over fiberglass suffice and be preferable for the inside wheel wells...

I would hesitate to line the fenders with metal.
It would be the perfect way for moisture to become trapped.
It would be tought to get a perfect seal, and then if you did, it would be near impossible to tell if the seal had broken.

My vote would be to simply seal the wood well with several coats of oil based paint or urethane, then give it surface protection with rubberized undercoating.
Wood wheel wells are not a new thing, and work best when left uncomplicated.

Rob

[Ira]

My vote would be to simply seal the wood well with several coats of oil based paint or urethane, then give it surface protection with rubberized undercoating.
Wood wheel wells are not a new thing, and work best when left uncomplicated.

Rob

I'm glad you posted this. I was debating how to do mine, but you have me convinced. I'm just afraid of using the rubberized stuff, or ANYTHING that I can accidentally glop on my sides.

[toypusher]

You guys should consider Rhino-Liner or similar product. You can buy some of it in a can and brush it on yourself or go and have it sprayed on.

[Ira]

Can you buy a small can of it?

My TD only has 2 fenders. (Well, it ALMOST has 2 fenders.)

[48Rob]

Ira,

Blue three day release painters tape will prevent that overspray from ruining your varnish.
A little mineral spirits on a rag will clean it right up as long as you do so while it is still wet.

A windless day helps a lot too.

Rob

[48Rob]

Hi Kerry,

I'm not trying to bash your choice, but I've had several bad experiences with that type of coating...
Perhaps those I've encountered were improperly applied...


Products that have a very thick coating, like bed liner, are fantastic protection against the rough and tumble abuse some beds get.

The problems I've experienced with them occurrs when the liner cracks, or separates, develops a hole, etc.
Once this happens, moisture, dirt, etc. makes its way behind the liner, and rusts the steel.
If applied to wood, the wood rots.
Because the crack or separation is usually small, the damage isn't noticed right away, and the surface the liner is supposed to protect deteriorates unnoticed.

Fiberglass, and powder coated surfaces are, at least in my part of the country, famous for looking great, until one day, the coating falls off, revealing all the damage.

The rubberized undercoating I mentioned is no where near as strong and damage resistant as bed liner, but is very easy to check for damage, and recoat as needed.
The real preservative though, are the several coats of oil based finish.

Rob

[angib]

Dave,

On construction, I'd second those who think a metal liner isn't a good idea - I would go for epoxy-soaked wood or epoxy-glass sheathing if the fender is really thin.

The profile drawing of the Slumbercoach assumes that some original-shape fenders are used, such as these ones:



Here's two views of this sort of fender:




Now these are seriously difficult to make - the spherical (well, actually toroidal) part where the 3.5" cross section radius curves around the wheel is hard enough, but where it fans out into a duck tail at the back end is harder still.

I can't see how these can be done in strip wood and I wouldn't try to do this except in solid wood (well, MDF) in what the modelmaker's call the bread-and-butter method. Here's some photos where I used this method to build the head fairing on my motorcycle project:
The parts:

The parts assembled (the 'armadillo'):

The armadillo smoothed out - this took less than half an hour (but it is only small):


I very much like John/Micro469's ply-on-edge method and I'd agree if would look gorgeous - but then I've always thought edge of ply was attractive when most people don't. The chain-dotted lines in the side view drawing actually give the outer shape of the 'slices'.

I'll try to draw this out in more detail when I get a chance - the one thing to look at is the weight of the fender - the easiest way to make it would be quite thick and therefore heavy - if the slices are made thinner (ie, shallower) they won't necessarily hold their shape well.

Andrew

[Ira]

Oy vey.

I just wanna glop some stuff under there to protect the wood.

[surveytech]

I used a can of the spray on undercoater.......


It was 4 or 5 bucks at any autoparts store and did both of my big fenders easily.
easy to do. Just tape off the edges with some masking tape for the overspray.
You might want to do this before the outside finish goes on. Just in case.

Walter

[Juneaudave]

Thanks Andrew and John....I'm not discouraged, recognize the difficulty, and sure appreciate the help!!! I think the biggest initial probem I have is getting some gross overall dimensions so that the proportions are right. The actual curve geometry really isn't necessary...what the heck...I'll end up with one-offs anyway.

Stripping might be difficult, and a guy certainly doesn't want the weight, but one of the techniques I thought would make it possible would be the generous use of a "sabot" (something a fella in Belgium described when building his canoe). In essence, you would use solid wood in the tight curves and strip construction on the flat surfaces. Check this site out http://www.qajaq.be/38special-sabot.htm

[cracker39]

I know that my fenders, with tops of 1/4" plywood could get damaged from debris being thrown up if I were to drive fast on a gravel road, but I don't plan on being off smooth highways. So, I just sealed the undersides with several coats of varnish and primer, then painted on the Gardner's roof coating that I used under my floor. I'll just check them periodically to see if I need to recoat them.

[angib]

I think the biggest initial probem I have is getting some gross overall dimensions so that the proportions are right.

That's easy, I'll have that for you tommorrow - unless it's sunny and the bicycle beckons......

Stripping might be difficult, and a guy certainly doesn't want the weight, but one of the techniques I thought would make it possible would be the generous use of a "sabot" (something a fella in Belgium described when building his canoe).

The problem there is that the tricky bit is the outside 3" of the whole fender. You could probably bend thin strip around the curves, but the line of the strips would not follow the line of the fender - they would swoop all over the fender.

Of course the rest of the fender is no problem - that can be made from a single piece of ply!

I'll keep working on this.

Andrew

[Micro469]

I think the biggest initial probem I have is getting some gross overall dimensions so that the proportions are right.

That's easy, I'll have that for you tommorrow - unless it's sunny and the bicycle beckons......
I'll keep working on this.

Andrew

Andrew, if you're gonna post it , great, If yur gonna email it, send me a copy