DIY cratch cover

[Roy Steiner]

I am looking at making my own cratch cover. I know it may not be as good as buying one but as I am retired I have no surplus money and I would like the challenge anyway.  Should I be successful I may be looking at a pram hood also but one step at a time.  There are older posts on the subject but I could not find anything recent, hence the new thread.  In the first instance I am looking for advice on material and material sources.  I have seen acrylic, pvc and canvas and currently I am an open book for advice and preference.  I am looking for a good supplier for material; historically I know there was a forum member who either owned or work for a supply company but I cannot find the thread.  I realise many will advise against this route but the woodwork is not a problem to me and I am having expert support/training on the sewing aspect and have bought a sewing machine fit for purpose.  I only have a 36 foot narrowboat so the cover is a sensible size to work with.  Any advice and guidance would be helpful and may be helpful to others.  I do plan to make battery covers from the material in the first instance to familiarise myself with the nature of the product I choose to go for.

[Tonka]

6 minutes ago, Roy Steiner said:

I am looking at making my own cratch cover. I know it may not be as good as buying one but as I am retired I have no surplus money and I would like the challenge anyway.  Should I be successful I may be looking at a pram hood also but one step at a time.  There are older posts on the subject but I could not find anything recent, hence the new thread.  In the first instance I am looking for advice on material and material sources.  I have seen acrylic, pvc and canvas and currently I am an open book for advice and preference.  I am looking for a good supplier for material; historically I know there was a forum member who either owned or work for a supply company but I cannot find the thread.  I realise many will advise against this route but the woodwork is not a problem to me and I am having expert support/training on the sewing aspect and have bought a sewing machine fit for purpose.  I only have a 36 foot narrowboat so the cover is a sensible size to work with.  Any advice and guidance would be helpful and may be helpful to others.  I do plan to make battery covers from the material in the first instance to familiarise myself with the nature of the product I choose to go for.

Have you got a heavy duty sewing machine as you may need one

[blackrose]

29 minutes ago, Roy Steiner said:

I I do plan to make battery covers from the material in the first instance to familiarise myself with the nature of the product I choose to go for.

 

Canvas battery covers? Or have I misunderstood?

[Roy Steiner]

15 minutes ago, blackrose said:

 

Canvas battery covers? Or have I misunderstood?

If canvas is the material I choose; no.  If I choose acrylic or pvc, yes unless you think otherwise.  It would be purely to reduce corrosion as advised on my last boat inspection.  The bilge should be significantly less damp as I have sorted more effective water drainage, (rain used to flow into the bilge through drainage holes in the steps down to the cabin door).

 

45 minutes ago, Tonka said:

Have you got a heavy duty sewing machine as you may need one

yes thanks.

[LadyG]

I think I would avoid trying to have any windows, due to to the difficult technology. Zips are also tricky to tension. 

But you could have a rolling door/hatch cover instead.

I think there are videos on YouTube which promote the Sail Rite machine.

Fastenings should be rust proof, also s/s staples not the indoor type if you should choose to use a stapler. 

You may be able to get offcuts in Ebay if you don't mind different colours!

I would avoid pvc as I think a woven fabric will not let water enter via needle holes, but pvc might.

 

Edited January 13 by LadyG

[haggis]

Not so sure about the no windows. We have two windows on each side (which roll up) and without them I think the area under the cratch would be a bit dark

[Naughty Cal]

Don't waste your time and effort.

 

Save the money it will cost for a heavy duty sewing machine and materials, then save a little while longer and get a professional who knows what they are doing to do the job once and do the job right.

 

There is an art to making covers. That is why they are not cheap.

[LadyG]

3 minutes ago, haggis said:

Not so sure about the no windows. We have two windows on each side (which roll up) and without them I think the area under the cratch would be a bit dark

Yes, agreed, I was thinking about fixed windows, if they are in the roll up bit, the difficulty in tensioning would be avoided, as they would not be tight!

 

[Sir Percy]

Notes given by someone who DIY'd their own stern cover:

 

Quote

used a lighter waterproof material that I'll need to treat once a year, and choosing something that doesn't shrink loads is correct too. (https://www.amazon.co.uk/dp/B092DSRHY6?ref=ppx_pop_dt_b_product_details&th=1).

Eyelets were bastardised from my old pram hood that was falling apart since the attachment points were already on the hull in usable locations. If I was to do it from scratch then I'd imagine attaching the turn button fasteners would be the hardest bit. I used a tile scribe and a rubber mallet to punch neat holes that the prongs of the eyelets could fit through.

Stitching was the most worrisome part before I started so I bought a lot more fabric than I needed and used a lot of it to practice hemming and sewing panels together. Getting a 150cm X 10m fabric meant I only had to fabricate three panels (flat bit, sloping bit and a small one on top of the roof) and then attach them together which was hard because of the size. The seams I waterproofed with melt-in iron on tape that my mum had in her old sewing kit from the 80s!

Measuring was crucial so did it multiple times and mocked up with cheap tarp where I needed to - magnets meant this could be a one man operation. Coming back to those panels, I made it in three sections, working from the panel I had completed before moving on, any mistakes I did make were usually spotted and corrected.

 

[Puffling]

As well as getting plenty of practice making proper folded seams in heavier fabric, I'd urge you to make a paper template first, once your cratch board is constructed. That way you'll avoid wasted material through having to recut prices which are too tight at certain points. Also, have several runs of using the zip foot (you have got one, haven't you?) on your sewing machine. Quite a lot of the 'art' of learning to sew thick material is developing proper finger strength and avoiding catching unwanted material in a seam.

 

How do I know all this? I've made many items of outdoor equipment in waterproof and breathable materials, including a complete tent with flysheet and inner in lightweight nylon. The most demanding item was a rucksack (60 litres, with side pockets and full shoulder and waist harness), a rather similar project to what you'll be attempting. Seaming around corners and inserting zips so the pockets hung and opened exactly right took plenty of time and patience, but I enjoyed the whole thing. That rucsac lasted me 20 years and looked the bees bollox.

 

If you feel ready for the challenge, I'd say jump in and try it. These people might be a first stepping stone: asking for samples of your intended fabric is essential to know how you'll get on with it in real life

https://www.pennineoutdoor.co.uk/fabrics/waterproof-fabrics,-ultra-violet-stabilised-light-medium-and-heavyweight

[Tracy D'arth]

I know someone who did their own cover, it looks OK. If you want to know who and where (Cheshire ) PM me.

[Peugeot 106]

During lockdown I made sails for my dinghy using my wife’s domestic sewing machine. I have never sewed before and even though I say it myself they are perfect. It did take a long time but I did my research and took my time.  The machine is a Janome 525S around £200 new as used on Sewing Bee and it will do decent zig zag stitching. Yesterday I bought canvas to make a cover for my 16 foot sailing dinghy.
There is masses of info and videos on the Sailrite website. Good books include Canvaswork and Sail Repair by Don Casey and Complete Canvasworkers Guide by Jim Grant ( Sailrite) For materials Profabrics are very good and helpful and will send you samples. 
For a normal cover 300gsm Acrylic coated but look at Topgun, Odyssey, Weathermax. Have a chat with a cover maker eg Antrim. Basting tape is your friend. Stick it together before sewing. I would make patterns though I haven’t needed to yet

Best of luck. You will enjoy it and it makes a change from joinery, mechanicing, plumbing electrical,painting! You will save an absolute fortune. You could nearly buy a new engine with the money people spend on new covers in my Marina. 
My biggest problem is space as I live in a very small cottage
It’s great to be retired. Let us know how you get on

3 hours ago, Naughty Cal said:

Don't waste your time and effort.

 

Save the money it will cost for a heavy duty sewing machine and materials, then save a little while longer and get a professional who knows what they are doing to do the job once and do the job right.

 

There is an art to making covers. That is why they are not cheap.

Well you don’t seem up for a challenge or maybe you are talking from bitter experience?

[TandC]

We made both our pram cover and our cratch cover (twice after losing the first) and if you're on a budget, can go somewhere with a large table to work (we did ours outside but it was summer), and have decent machine then you can do a perfectly acceptable job and save £000s.

 

On material - PVC apparently is more prone to cracking in time due to the sunlight.  But it's smoother finish makes it easier to clean.  But most now seem to be made from PU-coated acrylic canvas, which is what we went with and it is readily available, well priced and easy to work with.   Ours has stood the test of time and I'm very lazy having only cleaned it a couple of times in 15 years...

 

This is the same stuff. https://www.profabrics.co.uk/products/sauleda-acrylic-canvas-pu-coated 

 

And then use the centrefold edge binding in colour matched: https://www.profabrics.co.uk/collections/marine-webbing-tape-binding-edging-tape/products/acrylic-centrefold-tape-22mm 

 

ANd make sure you use the UV stable thread or it will degrade. https://www.profabrics.co.uk/collections/marine-webbing-tape-binding-edging-tape/products/acrylic-centrefold-tape-22mm .    

 

We did sew in windows using PVC window material - but it does make the job a lot harder and increases the leaks... 2nd time cratch I didn't bother and instead put an perspex window into the cratch triangle for light.   In the pramhood, there is a rear screen which does make a big difference with light, but i wouldnt bother again as it does weep.

 

Sewing machine - all this talk of "you need an industrial machine" - you don't.  A good quality domestic machine with brand new (sharp) denim needles (size 90) are fine.   Our machine was bought new for the job, but it is just a  decent quality dressmaking machine. It did cost £400 brand new - just get one off eBay or Marketplace.  Ours was a Husqvarna Emerald and there are loads out there.  That machine easily punches through 4 layers of material (think of a rolled hem - that's 4 layers) plus edgebinding. And no dramas with the window material either.   Technique matters more - let it do the work - have someone to take the weight of the material - take your time etc.  

 

Cratchboard - made ours from painted wood - and you can buy the "lift the dot" or turnbuckle fittings online https://www.profabrics.co.uk/collections/marine-fasteners-turnbutton - i used turnbuttons on ours, and they work well.  

 

For the pramhood - I can't remember where i bought the stainless tube... it was expensive.  316 stainless tube.  https://www.seascrew.com/browse.cfm?MARINE-GRADE-STAINLESS-TUBE-AND-FITTINGS-&l=0000001282 - dont buy it from chandler - find a local metal stockholder and get them to order it - it was still pricey, but loads cheaper than a chandlery - this was 15 years ago tho.   And then you can buy all the fittings you need online to match.

 

I drew a template of my hoops on plywood and then used a heavy duty conduit bender, laying the hoop onto my template to match and tweaking it a bit more to get it exact.  You can buy all the deck fittings online - and you just drill and rivet them onto your hoop tube. 

 

I've got black nylon webbing straps, clips etc that hold my hoops up - all off ebay.. 

 

 

Back to the covers... 

 

You need to plan your design carefully - considering the ease of working with smaller sections that you join together, where are sewed joins going to lay when finished (avoiding any where rainwater may pool etc.)   Fit some of the key turnbuckles first - they give you tensioning points to work from. 

 

Make templates - i used old tarpaulins to make templates.  My technique was to do only basic templates just enough to get me started on the real material - and then i worked on these - putting them in place, pulling tight, working out where I wanted to fold for hems, pinning, taking it back etc.  A lot of the work was done with the actual cover itself.  

 

That PU coated stuff takes fold well - so you can fold a hem, pin it, and it will stay roughly flat - and that means you can take the cover back, adjust etc. Don't worry about the pin holes - they don't leak. Seems almost self-healing..

 

If you're not familiar with basic dressmaking techniques or how to use the machine, go to the library and get a book.  Practice.  Different stitch patterns are useful (which is why a good quality domestic machine is handy).   We used running straight stitch pattern for most, but also a tight zig-zag on areas of stress).

 

You need to take the thread off those big spools onto smaller domestic spools - ask on Facebook for empty thread spools.  Use an electric screwdriver and pencil to wind thread... do a quite a few.  Make up lots of bobbins of thread cos when it runs out mid-waythrough a vital seam it's a pain.  It's better to be wasteful of thread than have to start midway. 

 

Hmmm not sure i can think of anything else right now
 

The hardest part was getting good tension and allowing that the fabric will stretch out over time and become baggy.  I don't think the pram hood was great, but it doesn't leak.   

 

You want to avoid pools of water as that will leak through - so in your design, you want BIG curves on your hoops, steep angles on your cratch to help shed water down the fabric not letting it sit. 

 

It's hard to describe but I tried to avoid cutting/sewing the fabric and so have one long run off the roll for the pramhood top, with sides that fix to it.  But, I think that makes it more prone to stretching when it's a continuous length off the roll.  It may have gone less baggy if it was sections sewn together. 

 

 

Ours has totally done the job for 15 years - it doesn't look as good as a pro job - but I haven't spent £5k on it either. 

 

I'd put some photos up but the pram-cover is in storage as we have a deck house thing on in winter, and its cold outside.... 

 

 

Feel free to PM 

 

 

 

 

 

 

 

 

 

 

[Roy Steiner]

12 hours ago, Peugeot 106 said:

During lockdown I made sails for my dinghy using my wife’s domestic sewing machine. I have never sewed before and even though I say it myself they are perfect. It did take a long time but I did my research and took my time.  The machine is a Janome 525S around £200 new as used on Sewing Bee and it will do decent zig zag stitching. Yesterday I bought canvas to make a cover for my 16 foot sailing dinghy.
There is masses of info and videos on the Sailrite website. Good books include Canvaswork and Sail Repair by Don Casey and Complete Canvasworkers Guide by Jim Grant ( Sailrite) For materials Profabrics are very good and helpful and will send you samples. 
For a normal cover 300gsm Acrylic coated but look at Topgun, Odyssey, Weathermax. Have a chat with a cover maker eg Antrim. Basting tape is your friend. Stick it together before sewing. I would make patterns though I haven’t needed to yet

Best of luck. You will enjoy it and it makes a change from joinery, mechanicing, plumbing electrical,painting! You will save an absolute fortune. You could nearly buy a new engine with the money people spend on new covers in my Marina. 
My biggest problem is space as I live in a very small cottage
It’s great to be retired. Let us know how you get on

Well you don’t seem up for a challenge or maybe you are talking from bitter experience?

That is really encouraging .... thank you.  I will keep everyone posted.

34 minutes ago, TandC said:

We made both our pram cover and our cratch cover (twice after losing the first) and if you're on a budget, can go somewhere with a large table to work (we did ours outside but it was summer), and have decent machine then you can do a perfectly acceptable job and save £000s.

 

On material - PVC apparently is more prone to cracking in time due to the sunlight.  But it's smoother finish makes it easier to clean.  But most now seem to be made from PU-coated acrylic canvas, which is what we went with and it is readily available, well priced and easy to work with.   Ours has stood the test of time and I'm very lazy having only cleaned it a couple of times in 15 years...

 

This is the same stuff. https://www.profabrics.co.uk/products/sauleda-acrylic-canvas-pu-coated 

 

And then use the centrefold edge binding in colour matched: https://www.profabrics.co.uk/collections/marine-webbing-tape-binding-edging-tape/products/acrylic-centrefold-tape-22mm 

 

ANd make sure you use the UV stable thread or it will degrade. https://www.profabrics.co.uk/collections/marine-webbing-tape-binding-edging-tape/products/acrylic-centrefold-tape-22mm .    

 

We did sew in windows using PVC window material - but it does make the job a lot harder and increases the leaks... 2nd time cratch I didn't bother and instead put an perspex window into the cratch triangle for light.   In the pramhood, there is a rear screen which does make a big difference with light, but i wouldnt bother again as it does weep.

 

Sewing machine - all this talk of "you need an industrial machine" - you don't.  A good quality domestic machine with brand new (sharp) denim needles (size 90) are fine.   Our machine was bought new for the job, but it is just a  decent quality dressmaking machine. It did cost £400 brand new - just get one off eBay or Marketplace.  Ours was a Husqvarna Emerald and there are loads out there.  That machine easily punches through 4 layers of material (think of a rolled hem - that's 4 layers) plus edgebinding. And no dramas with the window material either.   Technique matters more - let it do the work - have someone to take the weight of the material - take your time etc.  

 

Cratchboard - made ours from painted wood - and you can buy the "lift the dot" or turnbuckle fittings online https://www.profabrics.co.uk/collections/marine-fasteners-turnbutton - i used turnbuttons on ours, and they work well.  

 

For the pramhood - I can't remember where i bought the stainless tube... it was expensive.  316 stainless tube.  https://www.seascrew.com/browse.cfm?MARINE-GRADE-STAINLESS-TUBE-AND-FITTINGS-&l=0000001282 - dont buy it from chandler - find a local metal stockholder and get them to order it - it was still pricey, but loads cheaper than a chandlery - this was 15 years ago tho.   And then you can buy all the fittings you need online to match.

 

I drew a template of my hoops on plywood and then used a heavy duty conduit bender, laying the hoop onto my template to match and tweaking it a bit more to get it exact.  You can buy all the deck fittings online - and you just drill and rivet them onto your hoop tube. 

 

I've got black nylon webbing straps, clips etc that hold my hoops up - all off ebay.. 

 

 

Back to the covers... 

 

You need to plan your design carefully - considering the ease of working with smaller sections that you join together, where are sewed joins going to lay when finished (avoiding any where rainwater may pool etc.)   Fit some of the key turnbuckles first - they give you tensioning points to work from. 

 

Make templates - i used old tarpaulins to make templates.  My technique was to do only basic templates just enough to get me started on the real material - and then i worked on these - putting them in place, pulling tight, working out where I wanted to fold for hems, pinning, taking it back etc.  A lot of the work was done with the actual cover itself.  

 

That PU coated stuff takes fold well - so you can fold a hem, pin it, and it will stay roughly flat - and that means you can take the cover back, adjust etc. Don't worry about the pin holes - they don't leak. Seems almost self-healing..

 

If you're not familiar with basic dressmaking techniques or how to use the machine, go to the library and get a book.  Practice.  Different stitch patterns are useful (which is why a good quality domestic machine is handy).   We used running straight stitch pattern for most, but also a tight zig-zag on areas of stress).

 

You need to take the thread off those big spools onto smaller domestic spools - ask on Facebook for empty thread spools.  Use an electric screwdriver and pencil to wind thread... do a quite a few.  Make up lots of bobbins of thread cos when it runs out mid-waythrough a vital seam it's a pain.  It's better to be wasteful of thread than have to start midway. 

 

Hmmm not sure i can think of anything else right now
 

The hardest part was getting good tension and allowing that the fabric will stretch out over time and become baggy.  I don't think the pram hood was great, but it doesn't leak.   

 

You want to avoid pools of water as that will leak through - so in your design, you want BIG curves on your hoops, steep angles on your cratch to help shed water down the fabric not letting it sit. 

 

It's hard to describe but I tried to avoid cutting/sewing the fabric and so have one long run off the roll for the pramhood top, with sides that fix to it.  But, I think that makes it more prone to stretching when it's a continuous length off the roll.  It may have gone less baggy if it was sections sewn together. 

 

 

Ours has totally done the job for 15 years - it doesn't look as good as a pro job - but I haven't spent £5k on it either. 

 

I'd put some photos up but the pram-cover is in storage as we have a deck house thing on in winter, and its cold outside.... 

 

 

Feel free to PM 

 

 

 

 

 

 

 

 

 

 

Thanks, really helpful and well appreciated

[rusty69]

We made one once using 630g pvc, width 2.5m, a hand cranked singer sewing machine and one of those cheap Hole Punch /eyelet setting tools.

 

The cost was probably less than a hundred quid, and so far it has been in service about 6 years. 

It's OK. It's functional and keeps the rain out and looks like it will last another 10 years at least.  It probably took four hours to make, and is passable.

 

What it isn't though is anything like as stylish as these multi panel jobs with windows and zipped opening. However, with a little more  effort our version 2 cover could be something approaching that.

 

We have also repaired the spray cover on the other boat. These things both cost many hundreds, if not thousands of pounds so I can see why you might like to have a go at making your own, particularly if you already own a heavy duty sewing machine.

 

Good luck with it. 

[blackrose]

1 hour ago, TandC said:

We made both our pram cover and our cratch cover...

 

Did you make your cratch from scratch? 🥴

 

23 hours ago, Roy Steiner said:

If canvas is the material I choose; no.  If I choose acrylic or pvc, yes unless you think otherwise.  It would be purely to reduce corrosion as advised on my last boat inspection.  

 

But you're talking about using thin, flexible PVC or acrylic material to make a battery cover rather than thick rigid sheet? I'm not saying it's not possible, I've just never heard of it. 

Edited January 14 by blackrose

[Roy Steiner]

6 hours ago, blackrose said:

But you're talking about using thin, flexible PVC or acrylic material to make a battery cover rather than thick rigid sheet? I'm not saying it's not possible, I've just never heard of it. 

I will probably include a frame underneath and sloped top to prevent pooling from condensation but battery covers are expensive and batteries are too large for me to be able to 3d print one in one piece.  It should work as it only has condensation to deal with but happy to hear otherwise if any one has any concerns.

[David Mack]

5 hours ago, Roy Steiner said:

 but battery covers are expensive

What sort of expensive battery covers are you thinking of? The ones I am familiar with comprise a piece of plywood with small section timber framing around the sides. Well within the capability of any DIYer and modest cost.

[Roy Steiner]

The plastic ones.  What you describe is what I will be making but with a cover over the timber section purely because I need to get a feel for the materials and it will be more damp resistant than plywood.

 

[Peugeot 106]

Roy I suggest you read what I’ve just written re keeping your bilges dry with a sunken step in your previous Danboline thread. You may not need to have wet batteries.

I feel guilty as I was too busy to explain this in the summer. And then forgot. Wet bilges used to be a terrible problem for me too but are now always bone dry

[Roy Steiner]

Thanks, very helpful, I am working on a similar solution.  My last inspection included the need to cover the batteries so in many ways my covers are to fulfil that request albeit probably less needed.

[Peugeot 106]

2 minutes ago, Roy Steiner said:

Thanks, very helpful, I am working on a similar solution.  My last inspection included the need to cover the batteries so in many ways my covers are to fulfil that request albeit probably less needed.

You can get plastic terminal covers that should satisfy the examiner (now that you should have a dry bilge!)

[Phoenix_V]

Re cratch cover (where did battery covers infiltrate this thread) If you want to keep it simple use the type of pvc sold for lorry tarpaulins a straight forward cratch cover shouldnt need any joints and the seams can easilly be welded with a hot air gun (and practice) hardware such as turn buckles and the like are readily available on the internet. Do make a template, a sheet of polythene will do fine.