Canvas vs. Dacron
- Thread starter dugkim
- Start date
Dave Wermuth
Who hid my paddle?
Hi Doug,
I recently obtained some dacron from Gil. the heavy stuff. And will use it on a new canoe I have partially completed. So, I think you should do the canvas first. then try dacron on your next project. Canvas covers imperfections. It doesn't let go all to once in a catastrofic event like dacron, (Not that I am an expert) I like the idea of the weight savings but I guess that dacron takes more skill. Again, not sure here.
I recently obtained some dacron from Gil. the heavy stuff. And will use it on a new canoe I have partially completed. So, I think you should do the canvas first. then try dacron on your next project. Canvas covers imperfections. It doesn't let go all to once in a catastrofic event like dacron, (Not that I am an expert) I like the idea of the weight savings but I guess that dacron takes more skill. Again, not sure here.
peter osberg
LOVES Wooden Canoes
All I can say is that it works for me and I have definitely stress tested it over the last 19 years.
I have made 3 of the big freighters and stripped one of the big canoes twice (23 ft freighters that are beach and surf launched), once because I wanted and see what, if anything, was happening to the fabric and to change colour; and after I had passed it on to the scouts, it had accumulated a lot of sand and gravel underneath the fabric, in both cases the fabric and cover was in nearly new shape and as strong as when it was put on.
I have had a highway guard rail go though the side of the oldest big canoe (my fault) with very limited tear to the fabric but 4 ft of 1 1/2x 1 1/4 ash inwale and 1 1/2 x 1/2 outwale plus 8 ribs and planking required some urgent attention (the 10 day 250 mile trip continued on the next day with a cheap and nasty repair)
I have given the routine that seems to work in my hands whether the canoe is 9, 12, 16, 18 or 23ft .
The rational is that weight is important and I am pushing my capacity to lift and move these boats particularly the big freighters. Having one part of my body forecasting changes in the weather is one thing, but a chorus is downright disconcerting. Using epoxy as a paint and a graphite epoxy paint/filler hardens the surface and seems to have made up for any lack of abrasion resistance as compared to new canvas. Twenty years of being left outside seems to have caught up to me and my canvas canoes faster than I want, I don't like to admit it but it is more than once over, so not having redo something I 'just did' (even if it is 15 or 20 years ago) seems to be a better and better idea. I know canvas can last a long time if it is kept dry and protected but my canoes don't get pampered that way.
I didn't realize it at first but one of the main reasons a canvas canoe gains weight so rapidly when dumped is that the under surface of the canvas wicks up the moisture. Another feature is the dacron is more stable than canvas and doesn't crack and buckle the way older canvas canoes do hence no need to do the repainting for waterproofing.
A selection of my stress tests are not all my stupidity, but my wife may have a different take on this. The list is not endless but it seems long enough. I must add that there are others who have participated as well in the stress testing.
One of my big freighters was dumped in a storm and surf (my friends son) the occupants picked up in response to parachute flares (don't expect those ****ty little things to work), but the boat and gear later pulled out of the beach (literally buried in the beach and surf) by several boats and only had paint scratches, The motor and gear was a different story.
I do know that canvas would not (and had not in my misspent youth) have survived some of the things I have done to the layered dacron fabric.
The 30-40% weight saving is real as is the durability.
I have made 3 of the big freighters and stripped one of the big canoes twice (23 ft freighters that are beach and surf launched), once because I wanted and see what, if anything, was happening to the fabric and to change colour; and after I had passed it on to the scouts, it had accumulated a lot of sand and gravel underneath the fabric, in both cases the fabric and cover was in nearly new shape and as strong as when it was put on.
I have had a highway guard rail go though the side of the oldest big canoe (my fault) with very limited tear to the fabric but 4 ft of 1 1/2x 1 1/4 ash inwale and 1 1/2 x 1/2 outwale plus 8 ribs and planking required some urgent attention (the 10 day 250 mile trip continued on the next day with a cheap and nasty repair)
I have given the routine that seems to work in my hands whether the canoe is 9, 12, 16, 18 or 23ft .
The rational is that weight is important and I am pushing my capacity to lift and move these boats particularly the big freighters. Having one part of my body forecasting changes in the weather is one thing, but a chorus is downright disconcerting. Using epoxy as a paint and a graphite epoxy paint/filler hardens the surface and seems to have made up for any lack of abrasion resistance as compared to new canvas. Twenty years of being left outside seems to have caught up to me and my canvas canoes faster than I want, I don't like to admit it but it is more than once over, so not having redo something I 'just did' (even if it is 15 or 20 years ago) seems to be a better and better idea. I know canvas can last a long time if it is kept dry and protected but my canoes don't get pampered that way.
I didn't realize it at first but one of the main reasons a canvas canoe gains weight so rapidly when dumped is that the under surface of the canvas wicks up the moisture. Another feature is the dacron is more stable than canvas and doesn't crack and buckle the way older canvas canoes do hence no need to do the repainting for waterproofing.
A selection of my stress tests are not all my stupidity, but my wife may have a different take on this. The list is not endless but it seems long enough. I must add that there are others who have participated as well in the stress testing.
One of my big freighters was dumped in a storm and surf (my friends son) the occupants picked up in response to parachute flares (don't expect those ****ty little things to work), but the boat and gear later pulled out of the beach (literally buried in the beach and surf) by several boats and only had paint scratches, The motor and gear was a different story.
I do know that canvas would not (and had not in my misspent youth) have survived some of the things I have done to the layered dacron fabric.
The 30-40% weight saving is real as is the durability.
OP
OP
dugkim
LOVES Wooden Canoes
Fabric Weights...
I notice in surfing for Dacron on the internet that it is available in three weights; 1.8, 2.7 and 3.7 ounce. Which do you use? How many layers are installed and assumming you use the 2.7 ou and typical layering, is it still 30-40% weight savings? Also what about the Dacron tape?
I notice in surfing for Dacron on the internet that it is available in three weights; 1.8, 2.7 and 3.7 ounce. Which do you use? How many layers are installed and assumming you use the 2.7 ou and typical layering, is it still 30-40% weight savings? Also what about the Dacron tape?
OP
OP
dugkim
LOVES Wooden Canoes
Hi Dave
Perhaps I will have more projects in the future, but I am so overwhelmed with the work I have on this, the first one, that I don't see myself getting the bug to continue to collect and redo canoes. I love this canoe and want it to be in my family for generations, so I want to do it right (for me). The general concensus that "light is right" or that the lighter canoe gets more use...i have to agree. Already my canoe is an 18'er and will weigh quite a bit. If I can effectively eliminate 30-40% of the finished fabric weight, even if it is more complicated to apply, and eliminate all mildew problems as well, then sign me up...i am interested.
Dave Wermuth said:
Perhaps I will have more projects in the future, but I am so overwhelmed with the work I have on this, the first one, that I don't see myself getting the bug to continue to collect and redo canoes. I love this canoe and want it to be in my family for generations, so I want to do it right (for me). The general concensus that "light is right" or that the lighter canoe gets more use...i have to agree. Already my canoe is an 18'er and will weigh quite a bit. If I can effectively eliminate 30-40% of the finished fabric weight, even if it is more complicated to apply, and eliminate all mildew problems as well, then sign me up...i am interested.
Andy Hutyera
The Red Canoe Guy - Life Member
Pete,
I'm interested too. How about some more specifics. What weight Dacron, where to buy, more details on the filler and where to get it? Do you stretch the Dacron like canvas or does it heat shrink. I'm about to build a couple more canoes and have seriously been considering Dacron. I've looked at some of Pam Wedd's canoes and was really impressed with her Dacron covering. I too am feeling that the canoes are getting heavier and the hills higher and steeper, so the weight reduction is a big factor. The durablilty of Dacron is also a big plus. The only down side I'm aware of is that the filled Dacron does not protect the hull from pressure gouging. The wood tends to crush through the Dacron. Filled canvas is tougher in this regard, but I'm willing tolerate this in trade for the other good qualities of the Dacron covering.
I'm interested too. How about some more specifics. What weight Dacron, where to buy, more details on the filler and where to get it? Do you stretch the Dacron like canvas or does it heat shrink. I'm about to build a couple more canoes and have seriously been considering Dacron. I've looked at some of Pam Wedd's canoes and was really impressed with her Dacron covering. I too am feeling that the canoes are getting heavier and the hills higher and steeper, so the weight reduction is a big factor. The durablilty of Dacron is also a big plus. The only down side I'm aware of is that the filled Dacron does not protect the hull from pressure gouging. The wood tends to crush through the Dacron. Filled canvas is tougher in this regard, but I'm willing tolerate this in trade for the other good qualities of the Dacron covering.
peter osberg
LOVES Wooden Canoes
I found the "stits aircraft" manual very helpful, especially at the start.
-have not used the taping much (I tried it) as it creates a line that can be seen on the fabric. The heat shrinking is really easy, (I have found it easier than the canvas thing) although I would have saved myself some flack if I had just bought my own iron at the start instead of 'ruining' my wife's favorite iron... although I have to admit it wasn't quite the same after I had used it. You can do touch up any loose areas in the heat shrinking fabric after the first coat of polybrush which gums up the iron surface a bit and the polytack also gums up the surface of the iron (hardly at all was my line).
-used 2.7 fabric and multiple layers on the bottom of the big canoes. -Pressure gouging is a non issue to me although the thinner covers could show up some planking imperfections. Part of the benefit of this routine is the build up of thicker covering where you actually need it. When I bench tested the multiple layers, it exceeded any toughness I had come across with canvas. Field tests were largely of the unplanned variety.
-made a frame kayak as a test of the fabric at first, and it may not have been a bad idea in retrospect.
-started buying from a local home-built aircraft supplier, and since they have moved now, I just phone in my order
-the organic filter masks are a really good idea when working with the stinky coatings........they actually work, I forgot I was having my blood work the day after I did a paint job......only to find there was no(!) effect on my liver enzymes the next day....an unplanned endorsement of those organic filter masks.
-using the epoxy as a paint/reinforcing of fabric/ripstop effect and a graphite epoxy paint is effective as a filler, the weave is not visible after the primer and colour coat.
-have not used the taping much (I tried it) as it creates a line that can be seen on the fabric. The heat shrinking is really easy, (I have found it easier than the canvas thing) although I would have saved myself some flack if I had just bought my own iron at the start instead of 'ruining' my wife's favorite iron... although I have to admit it wasn't quite the same after I had used it. You can do touch up any loose areas in the heat shrinking fabric after the first coat of polybrush which gums up the iron surface a bit and the polytack also gums up the surface of the iron (hardly at all was my line).
-used 2.7 fabric and multiple layers on the bottom of the big canoes. -Pressure gouging is a non issue to me although the thinner covers could show up some planking imperfections. Part of the benefit of this routine is the build up of thicker covering where you actually need it. When I bench tested the multiple layers, it exceeded any toughness I had come across with canvas. Field tests were largely of the unplanned variety.
-made a frame kayak as a test of the fabric at first, and it may not have been a bad idea in retrospect.
-started buying from a local home-built aircraft supplier, and since they have moved now, I just phone in my order
-the organic filter masks are a really good idea when working with the stinky coatings........they actually work, I forgot I was having my blood work the day after I did a paint job......only to find there was no(!) effect on my liver enzymes the next day....an unplanned endorsement of those organic filter masks.
-using the epoxy as a paint/reinforcing of fabric/ripstop effect and a graphite epoxy paint is effective as a filler, the weave is not visible after the primer and colour coat.
OP
OP
dugkim
LOVES Wooden Canoes
Let me try...
Okay let me try an piece the steps together here:
1) cut and staple dacron to the hull one layer at a time.
2) apply some type poly"something" bonding agent.
3) heat shrink the dacron tight by iron or heat gun.
3) apply more layers in service areas
4) spray primer coat
5) spray grahpite enamel color
6) spray clear coat?
Okay let me try an piece the steps together here:
1) cut and staple dacron to the hull one layer at a time.
2) apply some type poly"something" bonding agent.
3) heat shrink the dacron tight by iron or heat gun.
3) apply more layers in service areas
4) spray primer coat
5) spray grahpite enamel color
6) spray clear coat?
peter osberg
LOVES Wooden Canoes
the steps are in the thread about pa's canoe,
-I would use the aircraft glue (polytack is the brand name) along the margins as per the instructions in the 'stits' manual (it is a brand name) not tacks
-use an iron (more useful in getting all the wrinkles out) to heat shrink the fabric to a nice tight fit and smooth the edges (very slick and fast once you get the idea)
-polybrush(a brand name) is the vinylizing waterproof paint that remains very flexible and is the 1st layer, it is also an adhesive so if you are proceding without a sand and gravel catchment layer you need to have a layer to prevent adhesion (between the fabric cover and the underlying wood layer), hence the saran wrap layer on top of the wood
-use aircraft glue (polytack) to secure the margins for additional layers the same as the 1st layer and smooth with the iron:-then epoxy/epoxy graphite -add layers as requirement for abrasion etc.
-I am partial to using a brush for the undercoat (then sanding) and then a brush for the colour coat, as oppose to spraying as I don't have a formal positive pressure suit and automotive spray booth.
If you are interested in this and want to try it, I would strongly suggest getting the stits manual, as their explanations are more complete than what you paraphased. I only follow the first part of their process, but it talks about how to do it, and explains fabric technology well.
-I would use the aircraft glue (polytack is the brand name) along the margins as per the instructions in the 'stits' manual (it is a brand name) not tacks
-use an iron (more useful in getting all the wrinkles out) to heat shrink the fabric to a nice tight fit and smooth the edges (very slick and fast once you get the idea)
-polybrush(a brand name) is the vinylizing waterproof paint that remains very flexible and is the 1st layer, it is also an adhesive so if you are proceding without a sand and gravel catchment layer you need to have a layer to prevent adhesion (between the fabric cover and the underlying wood layer), hence the saran wrap layer on top of the wood
-use aircraft glue (polytack) to secure the margins for additional layers the same as the 1st layer and smooth with the iron:-then epoxy/epoxy graphite -add layers as requirement for abrasion etc.
-I am partial to using a brush for the undercoat (then sanding) and then a brush for the colour coat, as oppose to spraying as I don't have a formal positive pressure suit and automotive spray booth.
If you are interested in this and want to try it, I would strongly suggest getting the stits manual, as their explanations are more complete than what you paraphased. I only follow the first part of their process, but it talks about how to do it, and explains fabric technology well.
peter osberg
LOVES Wooden Canoes
As mentioned somewhere before, I have used 1 to 6 layers in different situations and areas. 6 is probably overkill, 1 light duty only. The most common routine is 1 layer of fabric with the polybrush, then an additional fabric layer-then epoxy- then graphite epoxy paint-then undercoat- then colour coat... for a general duty canoe, if the canoe was for tripping and rapids I would recommend 3 layers, if you have a particular affection for rocks (or are prone to worry and paranoia) add another layer. If you manage to poke a hole in the fabric then duct tape or pine gum is all that is required to repair, the explosive or extended tear concept is fiction(in my experience) as far as this routine is concerned. To damage the fabric you have to be breaking planking and or ribs, the most common situation of damage is to crack ribs and planking and have the fabric unscathed.
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