roundover on the bottom of the TD

[faithie999]

the hymnal says to put a 3/8 inch roundover on the bottom of the TD, using a sander, to facilitate fiberglassing.

did anyone use a router instead?  seems like a tedious process using a sander.  I don’t think the plywood on the sides will chip out given the fiberglass and epoxy giving it strength.

ken

[stevie]

I used a router on my TD’s bottom.  It went quickly and without incident. Did same for butt block as well.  No doubt other builders have done the same with similar results.

If you’re contemplating omitting the roundovers, I wouldn’t.  Fiberglass cloth will give disappointing results when attempting to negotiate right angles.  Plus, rounded edges are more aesthetically pleasing.

 

[Bob D.]

Thanks for the tip.  I was planning on using a router and am glad somebody tried before I did.  What radius did you use?  Something like half inch?  3/4″ ?    I will be flipping it over tomorrow to deal with the butt block and prep for glassing so I’m nearly ready to round over.

 

I need this thing done for 6/24 and 6/25 (ARRL Field Day (ham radio thing)).    One door has been cut out after epoxying in the window sill and door stiffener.  It came out and held its shape… for now.   I just epoxied in the door stiffener on the other side earlier today so I’ll cut the door out tomorrow.   I managed to cut the fiberglass for one side short so instead of patching in a very visible place, I just used a whole new piece.  I *might* have enough for the bottom but wasn’t taking chances and ordered 5 yards from CLC earlier this week and it showed up today so I’m ready to go.

 

-Bob

 

-Bob

[faithie999]

Bob–we’ll see what Stevie’s answer is, but I used 3/8″ roundover on the butt block.  the book says 1/2″, but a 3/8 roundover plus 3/8 fillet nicely fit with the 3/4″ thickness of the butt block.  as for a bit, my 3/8 roundover bit assembly with bearing is too long and bottoms out on the top of the underside preventing the bit from coming in contact with the butt block.  so, harbor freight to the rescue. they sell a CHEAP (meaning quality) set of bits that includes a 3/8 roundover with a guide post on the bottom that is short enough so it doesn’t bottom out.  the downside is that for 7.99 the set is high speed steel, not carbide tipped, so you end up burning as well as shaping the wood.  I’ll dress it up a bit with the sander but of course it won’t show.

on the sides, I can use my carbide-tipped 3/8 roundover with bearing.  but as for the front and rear, since the panels angle out from the bottom, the bearing will keep the bit too far away from the edge to get a full 3/8.  I’ll have to finish the roundover with the sander.  I  dare not try to freehand using a bit without a bearing.

good luck getting your camper ready for the ARRL event!

ken

 

[stevie]

I used 3/8″ too. Also did the butt block roundover prior to gluing to TD bottom.

Whenever my build was at a standstill – waiting for epoxy to cure, bad weather, etc, I scanned ahead in the manual. If something could be assembled, sanded, glued, or varnished beforehand, it often saved a beau coup of time at a later date.

Not really related… I had more Cell-O-Fill than wood flour and subsequently ran out of the latter. I successfully used wheat-flour as a substitute. It was a bit darker than the supplied wood flour, but you could use a bit of Cell-O-Fill to lighten the epoxy mix.

I experimented with ashes from my woodstove too, and it turned the epoxy mix almost black. The only location I used it was the filling gap above the eyebrow (p. 250-251). It provided a subtle “racing stripe”. I recall that CLC used pinstriping on this location. In retrospect, I wish I’d added copper powder instead of ashes for effect. I suppose one could use many colored powders instead, though test for compatibility beforehand.

• This reply was modified 6 years, 10 months ago by stevie.
• This reply was modified 6 years, 10 months ago by stevie.

[JoAnnG]

I too am planning on putting the radius where the sides join the floor with a router.  I found that my sides came past the undersides of the floor when the keyed slots were fit between the sides and the floor.  Will be a bit tricky keeping the router bit square but they are pretty close to square as designed.

I will round over the bottom of the center join bar when I flip the camper back over.  I am thinking of adding two more bars parallel with the center bar so that the bottom is stiffer and sits across all of the rails in our trailer (We are using the Northern Tool 5′ x 8′).  From my initial measurements the camper fits exactly between the fenders. of the trailer.  The Engineer in me likes this idea better than attaching on the round pucks that support only in specific spots.

[faithie999]

the sides on my TD extended down past the floor, as well, about 1/4 inch.  after I flipped the TD over to glass the bottom, I used my small circular saw to shave off the 1/4″ excess.  then that provided a flat surface to run my router on.

when I was anticipating cutting the hatches and doors out of the TD, I looked around for a small circular saw that was easy to handle with one hand, and one that I could easily see the blade and the cut line.  I ended up with the Dremel Ultra-Saw.  about $100 at Home Depot.  it comes with 4 blades, one of which is a fine-tooth wood blade which worked great.  it is small enough that I could rest the front end of the foot on the cut line, then slowly plunge the blade exactly on the cut line. thanks to the fine-tooth blade and the fiberglass/epoxy on the shell, there was no chip-out.

for trimming the 1/4″ extra from the sides, I marked a cut line with a sharpie.  I left the sides just a slight amount proud and finished it flush with my orbital sander.

[stevie]

I have an Ultra-Saw too.  Did some trim work just as faithie999 described and the camper and an earlier pirogue build.  Dremel has created a fine tool to have in your collection.

There is less positive pucker-factor though when using a flush trim bit on the router.  

[faithie999]

you’re right–a flush-cut router bit would have been the way to go.  I undercut on one side, but fortunately not enough to show after the 3/8 roundover.

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