June 8, 2011

Canoe Mold Build Day 7

Foam shaped from side

Foam shaped from side

Day 7 was all about the shaping of the foam. Tony quickly stepped into the role of master shaper while Kevin worked on rough shaping and I did foam strengthening. By the end of day 7 we had completed the shaping and sanded the surface of the foam smooth.

Shaping

Tony shaping foam

Tony shaping foam

Kevin shaping foam

Kevin shaping foam

In the day 6 post I mentioned that a rasp was an essential tool for shaping the canoe according to our testing. In day 7 as we went about shaping the canoe we realized the rasp was AMAZING for achieving a uniform and desired shape. While the dual action sander was great for smoothing the rough surface the rasp left behind, it was poor tool choice for shaping the foam. The sander with an aggressive 60 or 80 grit had a tendency to dig into the surface too much on account of the 5″ disc of the abrasive areas. The rasp was about 2″ wide making it just a bit wider than the foam strips. This 2″ of width was combined with a diagonal stroke across the mold a very uniform and consistent cut across the foam was delivered. Kudos to Tony for discovering this technique. The only major challenge we had with the rasp, and the sander, was the foam vibrating or bowing in when running the tools over it.

Strengthening

Foam reinforcement

Foam reinforcement

To overcome the challenge of the foam strips flexing when rasping and sanding I embarked on a mission to strengthen the foam strips from within the mold. To strengthen the foam I added strips inside the mold in between the strongbacks that went laterally across the foam strips. I used scrap pieces of foam from the initial foaming of the strongback. I broke pieces ranging from 3″ to 6″ depending on the curve of the area and then I laid a nice 1/4″ bead of hot glue across the piece. Once the glue was in place I would position the piece and hold it there until the glue setup. It was a slow process that was hard on the back due to being in a laying position on the ground. While the process was slow (I actually did this over the next 4 days before the official day 8 meet of Kevin, Tony, and I)  it did yield great results. The strength across the mold was MUCH stronger and allowed for much faster shaping. Moran mentioned that 5/8″ plywood for the strongback offered more glueing surface for the foam that resulted in greater strength, although we used 1/” plywood. After going through this strengthening process I would recommend using 5/8″ plywood for additional foam strength. If I build a second mold I will be using the 5/8″ thick plywood.

Sanding

Once the right lines and curves of the canoe are achieved with the rasp it was time to use a dual action sander with 80 grit sand paper to get the smooth surface that we need for mudding the canoe. The sanding process did not take that long since it was just a smoothing and not a shaping operation. It was helpful as the canoe achieved a smoother surface as we did find areas that needed more shaping to achieve the desired curve or line. As with each step of this process just take your time and be patient. While for most parts of the build the next step offers you the ability to correct issues with the previous step, it is best to avoid having to fix these issues later. Care now will save time later.

Bow & Stern Trimming

Foam shaped from top

Foam shaped from top

Trimming of the bow and stern seemed daunting as mistakes here lead to time consuming foam repairs, but it was fairly simple. Just take your time and be gentle. We used a flat hand saw with a flexible blade. We ran the blade down each side of the bow/stern while flexing the blade to match the contour of the surface leading up to the bow/stern. After we ran a cut down both sides on the bow/stern we had a very nice edge. While the foam did have some gaps in it due to placement of the foam it was no big deal as we were able to glue chunks of foam in to help fill those spaces. Remember Moran did mention that you can have up to 1/2″ gaps in the foam as the drywall can fill it. However, I would not recommend exceeding a 1/4″ gap between the foam. The mud in the 1/2″ gaps takes too long to dry and is quite brittle. It is a better use of your time to glue in some small chunks of foam.

In ensuring that the bow/stern were true we did use the measurements from the bow/stern sketches to help validate that are work truing the mold player through into having a true bow/stern. As we were shaping and sanding the bow/stern they seemed to look crooked or off, but by the measurements and plumb they were correct.

Key Learnings

  • Rasps are great for shaping. Be sure to use a diagonal pattern as you run the rasp across the canoe.
  • Adding additional support inside the canoe to run across the 1 5/8″ strips of foam will greatly increase the effectiveness of using the rasp and shaping consistently
  • A dual action sander with 80 grit paper is the way to smooth out the rough surface left behind from the rasp.
  • The shaping process takes much longer that you would think.
  • Using measurement from the bow and stern sketches is helpful for accurate shaping.
  • Avoid gaps larger than 1/4″ in the foam. Moran says 1/2″ but it takes too long to dry and ends up being too brittle.
~Nathan

June 2, 2011

Canoe Mold Build Day 6

Kevin and Tony reviewing station plans

Kevin and Tony reviewing station plans

Last night we made some great progress in building the mold despite the setback of the mold not being true and plumb. Plus we have added a fourth member (Amy is #3) to the build team, Tony. The wolf pack of three is now four! Tony is joining the build as a full time participant whereas Amy is still a part time contributor. For day 6 we focused on plumbing/truing the mold and did some testing for how we are going to shape the foam.

Plumb & True

Kevin and Tony truing the mold

Kevin and Tony truing the mold

As we started the night by investigating the crooked bow we quickly realized the entire strongback was twisted. So the bow and stern were both off. After investigating our options which included cutting back the foam from the bow/stern to straighten the frame, we decided that twisting the vertical 2″x6″ of the strongback would allow us to straighten the bow/stern without any destruction to the mold.

To accomplish our twisting of the vertical 2″x6″ of the strongback, we attached 2″x3″ (scraps) to the vertical of the strongback on each side at each set of legs. Then Tony and Kevin used these 2″x3″ supports to twist the strongback into place where I welcomed them with a 3″ screw into the nearest leg of the mold. We did this to all four 2″x3″ supports one-by-one. The result was a bow/stern that were well within tolerances. Our horizontal 2″x6″ of the strongback was only off by about 1/8″ over the 16.5′ of the canoe mold. We were quite satisfied with this. What little effect this had on the bow/stern we will be able to take out in the shaping of the foam.

Shaping

Kevin rasping the the foam

Kevin rasping the the foam

Next up is the shaping of the canoe. In this part of the process we will use rasps, sandpaper, and drywall mud to give the mold the final details of the shape that will become our canoe. This is a part of the process that requires perfection. Every twist, bump, or cranny at this stage will be reflected in each canoe be build off this mold.

Me rasping the surface of the foam

Me rasping the surface of the foam

Due to the late hour we decided that we would line up the necessary tools and just experiment with techniques for shaping the foam. Then next week we would focus on actually getting the foam shaped and a first of the three coats of mud. In our experimenting we found that a 1.5″x12″ hand held rasp was a very effective way to take the rough edges off the foam. Due to the distance between the stations we did get flexing in the foam that was creating some unevenness in shaving off of materials. To help reduce this movement in the foam I started attaching addition foam to the inside of the mold. These additional supports were just pieces of scrap foam glued across multiple strips of foam from inside. The results so far with the additional support have been great.

Key Takeaways

  • Ensuring the strongback is plumb is essential prior to foaming.
  • Plumb the vertical and horizontal surface of the strongback.
  • A Rasp is key for shaping the foam to the final shape.
  • Hot glue does not like to be rasped. It likes to just break and chunk out.
~Nathan

May 22, 2011

Canoe Mold Build Day 5

Kevin and I’s approach on the this project has been a 2-part strategy. Part one is that we meet weekly on Wednesdays to work on our canoe, and between our weekly meetings we each pick up relevant supplies and tools for our next meeting. Last week we had to cancel due to scheduling issue so this past week we doubled up. Day 3 and 4 were Monday and Wednesday. With foaming taking longer than the single day we thought it would we figured Wednesday would be our big day of completing the foaming. As Wednesday wrapped up and I realized this was not the case a feeling of incompleteness started shadowing the week. Not to mention with just 24-hours until church there was a definite deficiency in spiritual carbs [See Is There An App for That – Grow]. This set me up for day five of the canoe build being Friday night. I was compelled to complete the foaming by the end of the week

Day 5

Foaming complete after 3 days of work

Foaming complete after 3 days of work

Late in the evening Amy and I decided to team up and finish the foaming. As I mentioned before the foaming is a two person operation so her help was essential. Plus she had prior experience as on day 4 she did help Kevin and I by holding pieces for us. In a short 2 hours Amy and I filled in the final top section of the stations/strongback with foam. It was awesome to see the entire frame covered in foam. Plus Amy is now officially apart of the canoe build with two nights of service under her belt.

Next Steps

The next step in the canoe building process is to sand the foam. As we sand the foam to an even and consistent surface we will be determining the final shape and countours of the canoe. This will definately be a time consuming endeavor as this is where we need perfection in our work. Once the foam is sanded a few thin coats of drywall mud will be applied and then it will be time for the fiberglass.

KEY LEARNINGS

  • Amy is an amazing wife (okay maybe I knew this already).
  • Friday night foaming with the woman you love is awesome.
  • I need to be more patient with the canoe building process.
~Nathan

Canoe Mold Build – Day 3, 4

Days 3 and 4 of canoe building have resulted in most of the mold being complete, or should I say we can at least “see” the canoe. All in all I would say that the foaming of the mold is taking much longer than I though. Kevin, Amy (yes she joined in too), and I have almost 30 hours into the foaming of the strongback and stations. Based off the book it seemed like in 4 hours Kevin and I would be able to square away the foaming, but I was wrong. We encountered many challenges along the way.

Bow/Stern Installation and Truing

Strongback alignment

Strongback alignment

We left on on day 2 with the stations attached to the strongback and the bow and stern built but not attached to the strongback. Attaching the bow and stern is straightforward as they both have vertical and horizontal square marks which you line up with the T shape of the strongback. The bow and stern attach to the front and end of the strongback, they do not go on the top of the strongback like the stations. Attaching the bow and stern is as simple as aligning the marks and attaching with a few screws.

Next we stepped into the alignment of the stations and bow/stern. The goal here is to ensure that all of the stations and the bow/stern are aligned to help create a straight uniform canoe mold. Failure to do so can result in a crooked canoe, which is not going to make a very good sea going vessel. To ensure alignement we attache a string from the stern to the bow. Next we look at the square marks that are on top of the stations (we put these marks there when we transfered the drafting templates to the plywood) and ensure they line up with our string. If they do not align, then we unscrew the station from the strongback and shim it until it lines up. We go up and down the strongback doing this as needed to each station. We also want to ensure that the bow and stern are both vertically plumb. In all honesty I am not sure that Kevin and I did and I have reason to believe our bow may be “off”. More to come on that later as Kevin and I uncover the issue.

Once all of the stations are aligned with the bow/stern on the stongback, and the bow/stern are plumb we tack a small strip of wood (.75″x.25″x16.5′) from bow to stern to ensure the top of the stations do not move as we start applying the foam. This strip of wood will be removed once we get towards the top of the stations with the foam. Kevin and I tacked the strip in using a brad nailer which worked great. Moran suggested using small nails which would work also, but if you have access to a brad nailer it really speeds up the process and reduce the likelihood of moving the stations out of alignment when hamming the nails in.

Foaming

The foaming process seems simple on the surface, but comes with many little gotchas that can be avoided with a little forewarning. Cutting the foam is simple work for a circular saw with an adjustable fence and a few 2″x4″s. While simple, cutting the needed 3-4’x8′ sheets of foam does take about an hour. The goal is to cut 1 5/8″ strips of foam in a trapezoid shape. This shape allows us to lay the foam over the curves of the stations and allow space for the glue to squeeze out.

Foam Cutting

To cut the foam set the blade depth to penetrate about a 1/16″ below the depth of the foam and set an angle of 8*. Lay a couple 2″x4″s on the ground. You will set the foam on the 2″x4″s to cut and give the foam strength as you gentle walk down the foam while cutting. To get the trapezoid shape you will make a cut going direction “A”, and then you will flip the sheet of foam over on the 4′ edge and make a cut in the oposite direction (B) on the opposite edge. As you repeat this operation of flipping the foam and changing the direction you are cutting from your will create strips that are a trapezoid in shape. You will need about 2.5 sheets of foam cuttup for a 16.5′ version of the James Moran’s Tripper canoe.

Foam Installation

Foaming up the strongback

Foaming up the strongback

The installation of the foam is where the foaming process “got out of hand” time wise. Glueing 1 5/8″x1″ strips of foam accross a frame of .5″ plywood is not as fast at one would think. As this is coming from a former custom cabinet maker who is being assisted by a fellow current custom cabinet maker and licensed contractor (Kevin). So technical skills sets with the tools and materials was not exactly the challenge. Our challenges fell into a few categories: tools, twists, not enough hands.

On day three we had a single generic Tool Shor (a Menards discount brand) glue gun. This glue gun had three forms of operation (it was a single setting unit): not hot enough to melt the glue, too hot of glue which melted the foam, and the right temperature of glue. This right temperature of glue was like a rare mythical beast like the Loc Ness monster. It was spotted so rarely that it’s existence was constantly in question. This left us playing a game of force the cold glue out and how much foam can we melt as we attach. Plus the hotter glue had us spending a lot of our time just holding the foam in place while we waited for the glue to set up. The takeaway here is to buy a two heat setting gun to give you some form of control in regards to the glue temperature.

Day 2 of foaming complete

Day 2 of foaming complete

Day four we greatly improved our foaming operation. Kevin picked up a second glue gun, and more importantly one with two heat modes. On day four we truely found our groove with foaming. Both armed with low quality glue guns we attacked the strongback/stations/bow/stern with foam and glue resulting in being about 90% complete with the foam operation. The most difficult part of the foaming process was dealing with the twisting of the foam from the first/last station to the bow/stern. Towards the top of the canoe the twist was light and not much of an issue. But as the foaming operation moved up the canoe (remember the canoe is upside down as we build it) towards the bottom of the canoe the twists became more harsh, and the hot glue was having issues hold the foam to the bow/stern. On these hard twists we ended up using large amounts of glue, held the pieces for a longer time to allow the glue to set, and at the most harsh twists we used pieces of foam that only spanned from the bow/stern to the previous station.The fact of the matter is this is very challenging and will require you to excersize patience as you learn how to make the foaming of the bow/stern happen.

All in all the canoe molding is looking pretty good. We are almost done with the foaming which will then lead us into the sanding of the foam to create the final *perfected* shape of the canoe.

Key Takeaways

  • Alignment of the stations/bow & stern is CRITICAL!
  • Ensure the bow/stern are plumb. This is also CRITITCAL!
  • Foaming is a long process. Be patient. Plan to spend 2o hours on this process.
  • Definately ask a friend, spouse, neighbor, or child to help applying the foam.
  • Either ensure you have a good glue gun or ensure you have two lower quality glue guns.
  • Remember to have fun, you are building your own canoe!

 

~Nathan