Jump to content
Strawberry Orange Banana Lime Leaf Slate Sky Blueberry Grape Watermelon Chocolate Marble
Strawberry Orange Banana Lime Leaf Slate Sky Blueberry Grape Watermelon Chocolate Marble

Dr Bob

  • Content Count

  • Joined

  • Last visited

  • Days Won


Dr Bob last won the day on May 3

Dr Bob had the most liked content!

Community Reputation

2657 Excellent

Profile Information

  • Gender

Previous Fields

  • Occupation
    Passed it
  • Boat Name
    Stuc A' Chroin

Recent Profile Visitors

5313 profile views
  1. No. We took a sailing yacht from Grangemouth to the west coast through the F&C in 2003 and that had a beam of at least 10 ft. It's not shrunk since then. Buy one down south and ship it up. Far more choice.
  2. GRP actually stands for glass reinforced polyester. GRP is therefore not a plastic and is not too difficult to bond to as the material has lots of oxygen molecules in it which can bond strongly to other things. Similarly with epoxies which again has 'active' groups as long as it abraided. Plastic on the other hand is a difficult issue. If it's Polyethylene or Polypropylene then it is very difficult to bond to. The material is all carbon and hydrogen atoms which don't allow much to stick. They are very hydrophobic so hate oxygen - which is what most adhesives use. Most adhesives tend to be hydrophilic. If it's PVC then it's easier as the Cl atom helps increase its hydrophilic nature. I seriously doubt any primer will work with PE or PP (polyolefins) other than flame treatment but maybe there is a proprietary primer for PVC or nylon. A primer for use on GRP used on polyolefis will not be any use.
  3. Epoxy for coating marine ply (edges) ALWAYS is 2 pack. Resin without hardener will NEVER cure. Cure is crosslinking of the polymer chains and that only occurs with hardener. Yes, premixed epoxies are made but these are usually sealant types. 2 pack epoxy for sealing marine ply will always be better than single pack alternatives. As Tony says, West are a good supplier of this type of epoxy resin.
  4. All the models now have 3-4 days of over 25°C - and many over 30°C in the SE of Ingerlund (Frid/Sat/Sun) but we will have to wait until 24-48hours to know about any precipitation. The models are good at predicting surface temperatures - but better at the 850hPa temps - ie the temps a bit up in the air where the pressure is 850hPa. See graph below. Just add 10-15°C to those numbers!!!!!
  5. On our previous boat, the vent line went down and up and so contained a lot of water. It was impossible to fill to full. I wonder if the OP is only getting the tank 1/3rd full and is being fooled by the tank level gauge (in the photo) which measures the head of water in the tank - and will give wrong readings if there is a vaccum being pulled as the tank is used. Sorting the vent line allowed us to fill the tank to full.
  6. Forecasting can be reasonably accurate a week or two ahead but for the last month all the major forecasting models have really struggled and even failed over 24 hours. Friday's hot day was clearly forecast the previous weekend and there is quite strong correlation between all the models today that we will get another 'plume' next weekend although some models are saying the heat won't disappear so quickly on this next one. (I read the same weather forecasting site as Matty😀.
  7. Desolation Row, Sad eyed lady of the lowlands, Lilly Rosemary and the Jack of Hearts. The guy is a legend and always will be! All 15 mins plus of sheer talent. Well done Bob!
  8. SML are not a major player in the formulation of epoxy coatings. They may be an agent for Jotun but that does not mean they know how well epoxies work. There has not been ANY miraculous breakthrough in the last 5 years that allows epoxies to be applied over soft coatings and perform the same as properly applied epoxies. If there was, do you not think that Jotun, Hemel and international would be touting it? It's a small company pushing their version of snake oil. SMLs blurb says "Ballastic Epoxy is a two-pack primer but it can be applied over existing bitumen paint and has all the protection of an epoxy primer which will allow the use of better quality two-pack topcoats." No, it does not have 'all the protection of an epoxy primer' - unless it is applied over an SA 2.5 surface. That statement is toatally misleading. You do not understand epoxy coatings. The MSDS sheet suggests this is just a bog standard epichlorhydrin based epoxy - no sexy modifications - so it aint goin' to be any thing different. As a guy who spent years formulating epoxies...I do. I could give you chapter and verse over why you cant apply them over a soft bitumen coating, but as you wont listen to Blackrose, it is not worth my time bothering. Dont waste your money. It may give you a few years more lifetime than blacking but at £60 for 5L (and the thickness you need to put it on at), it just aint worth it.
  9. The best way to guesstimate SoC is to have an accurate voltmeter and ammeter (preferably with amp hour counter). Rested voltage will tell you the state of charge (difficult to do when solar is working) and tail current down to 2% of battery capacity at 14.1+Volts charging will tell you when you have got to 100%. No gauge can be relied upon to tell you accurate SoC at all stages of charge - hence I use the word guesstimate. I would not use a volt or ammeter on the solar controller as it just tells you what the solar is doing. Get yourself a victron BMV 712 (or one of the cheaper models) or a NASA one which do the volts, amps and amp hour counting....but then you need to learn how to use them. They are not as simple as read the numbers and certainly dont rely on the SoC number they give you. You need to learn how to interpret the V and I readings.
  10. SML a big hitter in the marine coatings market. Er, no. International, Jotun, Hempel......yes!
  11. There are 2 types of coatings. Barrier and passive. Epoxies are barrier. They work by stopping water and oxygen getting to the surface BUT they must have excellent adhesion to the substrate ( i.e. Steel). That stops undercutting and rust penetration under the coating. They will not work well if applied over a soft single pack with poor adhesion i.e. Blacking. Now if the OP has found some super duper snake oil type modified epoxy that will work as a barrier over soft coatings then let's see the data sheets. In 40 years since being in the epoxy formulation game, none of the big boys have EVER achieved this! Trust me, I'm a doctor.
  12. I know how to do it. I just need the opportunity.
  13. Yea, but these LAs at the cheap end of the market dont do the job for long so the foreign ones may be a better bet to do the job.
  14. That's now 3 problems the OP has posted with a brand new boat. The toilet (which turned into a water pump and PRV issue), the water/oil in engine bilge and now the stern gland. Why on earth doesnt the OP ring up Colecraft and get them to sort it? It is a brand new boat (upwards of £100,000!). We have just bought one from Aqualine and I expect them to sort problems especially a drip every 10 secs from a stern gland that looks like it has no packing. If the OP tries to do any changes by himself ...ie new water pump because of a toilet issue, or changing the packing on a stern gland, then he could risk loosing the warranty on those bits. Colecraft are one of the best builders and will certainly sort out your teething issues. Get Colecraft to come out and sort out the stern gland. Rain into the engine bilge might be worth mentioning to them if a few of the drains have been blocked during manufacture....some boat builders have been known to accidentally fill drain holes with filler and paint during the build process!
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.