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April 5, 2023
05 Apr 2023
I’ve been told I must replace my rigging every ten years. Is there any proof of this?

It is often quoted that standing rigging should be replaced after ten years. There is no statistical or scientific logic that supports this ten year theory. Widespread application of stainless steel rigging started in the 1940’s and 50’s but nobody really knew much about the lifespan of this wonderous material. The old galvanised steel wire was a known quantity. The wire was wound around a rope core which was saturated with oil. Individual stays and shrouds would be taken down and soaked coiled up in barrels on Ensis Oil to recharge the core. Spliced terminations would be wormed, parcelled with tar soaked calico and served. The condition of the wires and splices could be monitored and replacement planned.

Stainless steel is different in that it shows little sign of ageing compared to ordinary steel. It corrodes in hidden places when deprived of the oxygen which enables the passivating layer of chromium oxide to form. Terminations are not hand made splices as before but machine made cold headings and forgings. Stainless steel is also subject to fatigue due to work hardening and cyclic stress loading. None of these defects can be seen to observation in normal use. The spar maker Per Selden tried to establish some kind of applicable measure of service life to stainless steel yacht rigging.

In the 1960’s he tabulated the data that was starting to be recorded on stainless steel rig failures and came up with a figure for typical safe service life of 20,000 miles. This data also generated the ‘bath curve’. This is a graphic representation of rig failure and can be imagined as the side profile of a domestic bath. The tap end is vertical and represents a high initial incidence of failure due to faulty manufacture or defective materials. The curve then runs flat along the bottom of the bath until after about 20,000 miles the curve rises slowly as failures start to occur from corrosion and stress fatigue due to cyclic loading and work hardening.

Some insurance companies jumped on this figure for policy terms, but as there was rarely any record of the usage of a vessel that they were insuring, they simply estimated annual usage at 2,000 miles, hence the infamous ‘ten years’ came into common usage with little real logic for time alone to become a sensible measure. In the present day of typical leisure use, the majority of private yachts do not get anywhere near 2,000 miles per year, whilst a very few could do 20,000 miles in a couple of years of blue water cruising.

Rig surveys are therefore a combination of the assessment of the visible condition and the evidence of the type and extent of the recent use of a vessel. Rigs that have been unstepped or de-tensioned annually during lay-up will usually be considered to have been maintained in better condition and likely to have a longer service life. The wire itself is very rarely the cause of failure which mostly occurs in the terminations or the chainplate structure. These can often be due to faulty manufacture or poor installation which can be identified by survey.

So, the age can give some indication of the length of good service life remaining in a rig, but it is only one factor in a complex assessment. Surveyors will usually make recommendations based on many factors which can suggest the potential for failure. These include the type and extent of use a vessel has had combined with physical checks of the condition of the standing rigging, Poor installation can be seen in the line of load to a termination, the correct sizing of cotter pins to forged fittings, the correct matching of forged or cold formed heads to mast fittings and measuring the roll or rotary swages to the standard tolerances.

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January 10, 2022
10 Jan 2022
Why do lead acid batteries slowly die and can they be recovered?

First we need to understand how battery chargers actually charge a battery. Switch Mode or ‘Intelligent’ battery chargers use a three stage process to recharge the battery most efficiently and safely. These stages are commonly described as Bulk, Absorption and Float.  The Bulk stage makes up about 80% of the recharge and the current is held constant and the charging voltage steadily increases as the battery fills.

When the charging voltage reaches about 14.1 volts it switches to the Absorption stage. The charger then maintains the voltage and the current decreases until the battery is fully charged. When the battery is fully charged the charger switches to the Float stage and maintains a reduced constant voltage of about 13.0 Volts which will maintain a full battery charge compensating for the small amount of self discharge that will occur.

All lead acid batteries will gradually lose power capacity due to a process called sulphation which causes a rise in the batteries internal resistance. When batteries are left at a low state of charge for a long period that process can be rapidly accelerated. A typical good battery has an internal resistance of about 4 ohms. A sulphated battery has higher electrical resistance which can be up to 50 ohms, by which time a battery is effectively dead.

As current is the ratio of voltage to resistance a sulphated battery will have much lower current flow and, in the charging cycle, the charger will reach its pre-set limit long before the battery has had time to accept a complete charge. In this case the battery charger will assume from the current flow that the charge cycle is complete and switch to the Float stage.

So, what is Sulphation and how can it be prevented? Flooded cell lead acid batteries commonly used on yachts consist of a number of plates of alternately lead and lead oxide in a cell filled with an electrolyte of weak sulphuric acid. Each cell produces about 2.1 volts so a typical 12V battery consists of six cells connected in series producing about 12.6 to 12.8 Volts when fully charged.

The lead oxide reacts with the sulphur to give the plates a positive charge. The lead plates react with the acid making them negative and thereby creating a potential difference between the pairs of plates. This chemical process also creates a solution of lead sulphate in the acid and as the battery is discharged the density of the lead sulphate increases.

When a battery is discharged to below about 11 volts the lead sulphate will begin to precipitate out of the acid electrolyte and form a soft film on the plates. When the battery is recharged the film will theoretically dissolve back into the acid. However, if the battery is left at the low state of charge for an extended period the soft film will slowly crystallize into a solid. This is the process known as Sulphation.

This process can be minimised in some batteries that are branded as Gel type or AGM (Absorbed Glass Mat) type. In these the acid electrolyte is held in a gel or in a saturated glass mat that effectively limits migration of the lead sulphate to the plates. These batteries are more expensive but should give a longer service life and more resistant to deep discharge.

In theory the sulphation process can be reversed and some devices are available called desulphators or desulfators. These work on the principle that the lead sulphate layer can be dissolved back into solution by applying very much higher charging voltages. Pushing high voltage into a battery with a high internal resistance will cause it to rapidly heat up. All battery charging will cause the release of hydrogen gas but boiling of the electrolyte can cause hydrogen gas release at explosive concentrations.

Therefore, these devices use pulses of high voltage that are too short to cause overheating but long enough to reverse the crystallization process. This recovery process can take days or even weeks to repair a batteries performance. The crystallization of lead sulphate has taken a long time to form on the plates in the first place so reversal is therefore also a very slow process, and it is not always successful.

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October 4, 2019
04 Oct 2019
What is ‘Plantation Teak’ is it the same as normal teak?

Teak is one of nature’s best natural materials which has led to the timber being grossly over harvested for both house and boat building. For example, the area of natural teak forest in Thailand decreased from 2,324,300 hectares in 1954 to about 150,000 hectares in 2000 (UN Food and Agriculture Organisation).

The felling of naturally grown teak has now been banned in all countries and only Forestry Stewardship Council (FSC) plantation grown teak is now legally available. This is fast growth timber developed by advanced tissue culture which allows teak trees to mature in less than 15 years, compared with over 40 years for traditional natural growth teak.

Plantation teak was first introduced in the 1990’s alongside traditional teak and was initially marketed as ‘Blonde Teak’ due to its pale colour. It is now the only variety available in quantity so the term has now been dropped. The colour difference is due to the wider bands of fast growing spring wood. A tree’s growth rings are made up of alternate bands of springwood and slower growing summerwood. There is no growth in the other seasons.

The springwood is a wide band and is light in colour; it is relatively soft and has a thin walled cellular structure. Summerwood is a narrower, darker band and the cell structure is much stronger. It is these alternating coloured bands that create the attractive grain pattern in the face of the timber. In fast growth teak the springwood bands are wider and softer due to the advanced growth rate, hence the grain appears lighter in colour.

The timber is also less durable than old growth teak. The use of pressure washers or deck scrubbing has the effect of scouring out the soft springwood leaving the harder summerwood and the caulking as raised ridges. This raised grain will then be rapidly eroded by foot traffic. For this reason a modern manufacture of fast growth, or Plantation Teak product should never by cleaned using a pressure washer or by aggressive scrubbing along the grain.

Many boat owners see brown stained water being washed overboard during pressure washing, and think it is dirt that they are removing from the surface. It is not dirt, it is the wood itself and its protective oils that they are washing overboard. Not only are they eroding the soft springwood they are also washing out the natural oils which protects the fibres and prevents shrinkage and warpage.

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May 24, 2019
24 May 2019
Engine oil lab analysis – is it worth it?

Engine oils can be examined for condition by spectroscopic laboratory analysis. It is often likened to a human blood test. In many ways it is a good analogy in that it flows round collecting residues created by the functions of various components. The analysis can test for various metals and minerals, some are intentional and some accidental;

Carbon or soot from combustion process, high levels are from poor combustion typical of a powerful engine that has spent most of it’s life idling in speed limited rivers.
Iron results from general engine wear, piston rings, bores, cams, crankshaft etc. All engines will gradually shed wear metals into the oil.

Nickel is alloy used in steel making as well as bronze. This will appear when Iron and bronze components wear. It is also used to plate components as a base for chromium plating.

Chromium comes only from plated components such as rings or bores, If an engine doesn’t have plated bores then high chromium levels means significant wear elsewhere.

Aluminium is mainly used for pistons so wear comes from piston skirts. Aluminium is also used as a bonding layer in engine bearings and can be a component of white metal bearings.

Copper is also used in engine bearings as a backing shell. It can also be copper oxide stripped from pipework in oil cooler cores

Lead is a principal element of most white metal bearing surfaces. This will usually be seen in similar quantities to tin

Tin and Zinc nearly all engines use white metal for big end and main bearing shells. White metal is made from various alloys of lead tin and zinc so all these metals will appear in various proportions.

Silicon is a generally atmospheric dust so intake air filtration should be looked. However there are some other sources such as anti foam additives for diesel fuel and gasket sealants

Sodium is a prime element in antifreeze so high levels usually originate from engine coolant leaking through head gaskets failure.

Boron is used as a corrosion inhibitor in antifreeze so can be seen in conjunction with sodium, however it is also used as a high pressure additive in engine oils.

Vanadium is used in surface coatings for hardened steel components such as turbo impeller blades and valves.

Phosphorus is a common component is bronze bearing bushes used for jack shafts, cam shafts and valve guides.

So the lesson from all this is that the real skill in the ‘analysis’ is not in the separation of the various elements within the oils, it is in translating those levels into some kind of identification of the problems that they are showing up. For instance, high levels of Boron can occur naturally as a oil additive, but seen with also high levels of Sodium can mean head gasket failure. Copper can be easily explained in an engine with an oil cooler but, if no cooler is fitted, then the source is almost certainly bearing wear.

The more information that there is about the engine and the oils will help greatly in the analysis. The grade of oil, type of oil etc is invaluable. The other issue which often skews the findings is engine hours since that last change. In a pre-purchase survey an owner will often underestimate the hours to give the impression that the engine has been maintained to the highest standards. Here he is shooting himself in the foot as the more hours the lower the rate of wear. This is particularly important in the levels of Iron because all engines will shed iron almost continually at a microscopic rate.

So oil analysis is not an exact science and the best that you will get is an opinion based on various findings. Here the analogy with a blood test is accurate because doctors will tell you that blood tests cannot detect diseases on their own. It is a tool to be used in conjunction with other symptoms. They will also tell you that there are many other factors that can give abnormal readings. The big difference with a blood test is that humans don’t have a total transfusion every year.

Doctors will also tell you that the most accurate tests are those made on a regular basis. These are no longer spot tests vulnerable to misdiagnosis for the reasons given above. This trend analysis gives a whole new insight observing progressive change in metals and contaminants. It is an easy process to send off a sample from every oil change, yet in many years of surveying I have yet to see a vessels maintenance log with annual oil analyses.

However, it is also a matter of economics. The cost of an engine oil analysis at £60 to £100 represents a fraction of 1% of the replacement cost of a powerful marine diesel engine. Most boat owners think marine insurance policies at about 1% are cheap when compared to motor insurance, so thinking about it as a cheap annual insurance policy makes a lot of sense.

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February 21, 2019
21 Feb 2019
Do I need to bond all my skin fittings to an anode?

All electrically conductive materials have a galvanic potential shown on a scale of voltages compared to a neutral reference. Noble metals such as gold and titanium have positive potential, and base metals such as zinc and aluminium have a negative potential. When two materials with different potentials are linked by an electrolyte, such as seawater,  current flows from the positive to the negative. Ions flow the other way resulting in erosion of the negative, or anodic material. It thus becomes sacrificial, protecting the more noble material from erosion.

It was common practice up to the 1980’s to link all metal underwater fittings with an electrical bonding circuit connected to a hull anode. There is about 0.3 volts potential difference between marine bronze used in fittings, and zinc used for anodes. With the introduction of more varied alloys and brasses used for marine fittings, the issues became more complicated. There can also be a potential difference of about 0.1 volts between noble copper alloys such as nickel bronze and manganese bronze, and cheaper copper alloys such as zinc brass used for popular valves and skin fittings.

For a sacrificial anode to be effective it needs to be close to the component being protected. This is because potential difference or voltages drop over a distance. It is termed ‘line of sight’ in that the anode needs to be able to easily ‘see’ the propeller or skin fitting it is intended to protect. This is why most anodes are located near the stern gear. The through hull skin fittings for heads compartments etc are often scattered around the hull bottom.

If all the skin fittings are bonded in one big circuit to an anode, they are also bonded together. This means that there is a possibility of an electrochemical reaction occurring between skin fittings which could be of slightly differing alloys. Although their potential difference will lower than to the anode, they are likely to be very much closer to each other than to the anode and therefore the potential difference can be actually be relatively greater. Best practice now is to ensure that  most through hull skin fittings are electrically isolated within the vessel, unless they are mounted close to the anode.

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January 18, 2019
18 Jan 2019
How do I stop my dark blue gel coat from going chalky

An application of a rubbing compound will remove the white chalking, but it is actually removing the thin film of resin that has oxidised. This is not a sustainable solution as it will eventually rub the gel coat away entirely. Some dark coloured hulls such as the Fairline Targas have a feature colour to the flanks and white to the hull below the chine.  This is achieved by spraying a thin coat of coloured gel into a masked up mould, which is then unmasked before the full thickness white gel is applied to all the mould.  Many owners have found that by regularly compounding the white chalking, eventually the chalky patches they are rubbing are actually the white gel coat showing through. This also applies to topsides with broad coloured sheerline stripes such as Etap and Westerly.

The only  effective solution is to polish the gel coat after compounding with a good polish. Wax-based products are widely used on gel coats but appear to give better protection than they actually do. Carnauba waxes provide protection from photo-oxidisation, however they give very limited protection from photoinitiation or UV attack. UV protection with carnauba wax begins to drop off in about 50 hours of exposure, with an almost total loss of protection after 250 hours.

The best method for resisting UV attack is to apply a UV resistant surface coating. Silicone waxes are UV resistant but the problem with silicone compounds is that they tend to migrate. Because they are difficult to bond, they tend to move to adjacent surfaces and into porous materials such as the polyester gel coat film. This can cause serious problems with subsequent bonding in the event of the gel needing repair or refinishing. There is also the possibility that silicone migration can cause embrittlement of the gel coat increasing the risk of crazing. Polishes containing PTFE, sometimes referred to on imported products as PTEF, provide the same protection as silicones but have none of the problems associated with it.

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December 11, 2018
11 Dec 2018
What is the best way to clean my teak deck?

The simple answer is carefully! Never use a pressure washer or a stiff brush. When pressure washing or scrubbing teak the brown staining to the water that is running off is not dirt, it is the wood itself that is being washed away.

Teak is one of nature’s best natural materials for decking. It has good non-slip properties and is particularly rot resistant due to the natural oils and minerals in its tissues. This has led to the timber being grossly over harvested for both house and boat building materials. For example, the area of natural teak forest in Thailand decreased from 2,324,300 hectares in 1954 to about 150,000 hectares in 2000 (Source: UN Food and Agriculture Organisation).

The felling of naturally grown teak has been banned in all countries and only Forestry Stewardship Council (FSC) forestry grown teak is now legally available. This is fast growth timber developed by advanced tissue culture which allows teak trees to mature in less than 15 years, compared with over 40 years for traditional natural growth teak.

A tree’s growth rings are made up of alternate bands of fast growing springwood and slower growing summerwood. There is no growth in the other seasons. The springwood is a wide band and is light in colour; it is relatively soft and has a thin walled cellular structure. Summerwood is a narrower, darker band and the cell structure is much stronger. It is these alternating coloured bands that create the attractive grain pattern in the face of the timber. In currently available fast growth teak the springwood bands are wider and softer due to the advanced growth rate making it particularly vulnerable.

The use of pressure washers or deck scrubbing has the effect of scouring out the soft springwood leaving the harder summerwood and the caulking as raised ridges. This raised grain will then be rapidly eroded by foot traffic. For this reason a modern manufacture of teak product or decking should never by cleaned using a pressure washer or by aggressive scrubbing along the grain. Modern ‘kit’ decks consist of thin veneers of teak laid over a plywood or an epoxy scrim base. The teak veneers and shallow caulking seams can soon be lost if badly treated.

If sanding off is necessary, it should be very light orbital sanding or across the grain. It can also be cleaned a chemical oxalic acid cleaner. A teak oil should then be applied which will retard the drying out and dying off of the cellular structure. The pale yellow/tan colour seen when the vessel was new is the sign of freshly cut wood. It is natural for the wood to age to a silver/tan colour. To try to maintain the ‘new’ wood look to the teak is to slowly destroy it and the cost to replace a teak deck to a 36ft yacht can be well into five figures.

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August 20, 2018
20 Aug 2018
Why is my tonnage different to my displacement? Are they not the same thing?

I am often asked this question. As an example, I recently surveyed a 60ft steel yacht in Greece. I asked about registration documents and was told that the only one that the previous owner had given him related to a different vessel. Not only were the weight and all the dimensions different, but it also said that it has two engines, when this yacht only had one! It didn’t help that the name of the vessel had also changed.

I studied the document and tried to explain to him that it was the same vessel. The registration said two engine sets but, as I pointed out, only one shaft. The 6 cylinder Ford was for propulsion and the four cylinder Perkins was the generator. Both had been strangely counted as an engine set for this particular registration and the engine numbers proved it. That still left the issue of the vessels dimensions so a more complex conversation ensued.

The purpose of a tonnage measurement is to determine the duties that a vessel has to pay when navigating a port or waterway. It is logical therefore that it should be based on the commercial potential of the vessel. Those capable of carrying the greatest volume of cargo have to pay the highest dues. The tonnage measurement is a calculation of the weight of cargo a vessel can theoretically carry, it has nothing to do with the displacement of the vessel.

The measurements are intended to calculate the internal dimensions of the hull and convert that into tonnes based on one tonne per cubic metre of cargo space. The original principal was to calculate the hull volume and then deduct working spaces such as engine room, steering space, crew quarters, tankage etc. Shipping authorities around the world calculated this in different ways according to local lore. This resulted in merchant vessels sometimes having up to twelve different ratings dependent on which port or waterway was charging them for passage.

In 1969 the International Maritime Organisation ratified the whole issue into one internationally accepted process and defined two different methods of measurement. For vessels over 24 metre Load Line Length a full hull volume measurement with deductions for working spaces has to be carried out. This is called the Assigned Formal Tonnage Measurement.  For vessels under 24 metres Load Line Length, which means the majority of pleasure vessels, a Simplified Measurement was established. This is simply 0.16 x the overall length x beam x depth of the hull. This does get a bit more complicated when there are different weather deck levels.

Load Line Length is defined as the length between the forward most part of the stem and the front of the rudder stock.  This is measured at 85% of the minimum moulded depth of the hull parallel to the waterline. My clients vessel had been built in 1965 in Australia and had a Maltese registration, so the full Load Line Length method with deductions had been used. It was no surprise that none of the apparent measurements, tonnage, length, engines etc appeared to match the boat he was buying.

Fortunately, since 1969 things are much simpler. Length etc will usually appear the same, but the vessels tonnage and displacement will always be different because they are not the same thing. Displacement is the weight of the vessel, whereas tonnage is the free internal volume of the hull in tonnes per cubic metre.

Medusa Marine are approved tonnage measurers for all Red Ensign flag states. For more information click here

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March 1, 2018
01 Mar 2018
Wet Rot, and Dry Rot, what’s the difference?

The two most commonly used terms for decay in wood are ‘wet rot’ and ‘dry rot’. They are often spoken about as if they were two completely different phenomena. Although there are many different species of fungi that can attack wood, the two types of decay are fundamentally the same. The exact biology is highly complex, but hopefully a simplified explanation is useful to boat owners to understand how to prevent and treat decay in their vessels.

Fungal decay begins as microscopic spores which can lay dormant in timber at low humidities for decades. Mostly they cannot be seen, but in high concentrations can appear as an orange dust. Seasoned timber has a natural moisture content of around 14%. When measurements are taken, the presence of paints, varnishes and penetrative treatments can raise the apparent moisture to 16% to 18%. Surveys will often show these figures without comment as they are quite acceptable.

When water soaks into wood and the moisture reaches close to saturation point at 28% to 30% the spores become active and germinate, multiplying rapidly producing more spores. As with all organisms, they need two things to grow, food and water. The water is present, and the food is cellulose which are the wood fibres. The fungus consumes the fibres and the lignin resin which binds the fibres is left weakened and soft. This is apparent to all as ‘wet rot’

What is commonly termed as ‘dry rot’ is most usually seen in buildings, but it was first observed in ship building. Ships hauled from the water for repair were often considered to be perfectly sound. When the wood started to crumble and collapse it was thought that a wholly new and different type of phenomenon was occurring in the dry wood. It was therefore termed ‘dry rot’.

Moisture needs to be at around 28% for the spores to germinate. But once they are active they can continue to consume the fibres with moisture dropping to as low as 20%. So, what was being observed by the shipwrights was just a continuation of a previous wet rot decay. The structure appeared originally to be sound because the moisture was actually binding the decayed wood together. When it dried the damaged wood would shrink, cracking into cuboid like cells, and the cell walls would eventually crumble to dust.

To combat decay requires three stages. First, and most obviously, the source of water ingress must be removed. But this is not enough, the wood must be dried in order to remove the water and stop the germination and thirdly the spores must be killed as otherwise they could continue to consume the cellulose, or at least lay dormant until re-activated.

Common fungicides are borate solutions or ethylene glycol which is most commonly found as blue antifreeze. These chemicals can be injected into the affected wood once it is dried. Once these have done their work and themselves dried, penetrating epoxies can be used to harden the wood. This process is only really practical however, in thin sections and cases of minor damage.

There are commercially available epoxy treatments which can claim to treat and harden damaged timber. But saturating treatments cannot penetrate already saturated wood. Also, even if the wood is dried, the saturation must pass right through the damaged wood and penetrate into the sound wood. Otherwise it cannot be guaranteed that all the active spores can be killed. Also, the epoxy not bind the whole together and reinstate the integrity of the structure. In larger sections and structural timbers, there is no real substitute to replacement of the affected timber.

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December 18, 2017
18 Dec 2017
Should I replace my mild steel keel bolts with stainless steel?

When considering replacing keel bolts, or any other fasteners, with a different material, a lot of things need to be considered. The designer and manufacturer will have specified a certain fastener for a reason, and that is rarely just a question of cost or ease of manufacture. There are two popular misconceptions about stainless steel. First that it is stronger than mild steel and second that it doesn’t corrode. Both are very significantly wrong.

The subject of corrosion is covered in another of my FAQ’s on this site. Basically, stainless steel corrodes (or more accurately erodes) where you can’t see it, whereas mild steel corrodes where you can see it. Furthermore, stainless steel corrosion creates crevices which can lead to fractures in the metal whereas mild steel corrosion is usually little more than a surface defect.

The issue of strength can be summarised by observing and understanding the head markings of the bolts. Mild steel metric bolts are marked with two numbers separated by a dot. The most common high tensile bolts being 8.8, 10.9, 12.9 and the strongest 14.9. Imperial sizes were marked with radial lines but we will concentrate on the more popular metric bolt grading system.

The first digit is the tensile strength, which is the load at which the bolt will fail. The second digit is the yield strength or elastic limit. This is the load at which the bolt will stretch by a certain percentage to absorb the load without suffering any permanent deformation. It can be seen from this that the tensile strength will always be more than or equal to the yield strength.

Stainless steel bolts are graded in a similar way but are marked differently. There is only one digit for the tensile strength because there is no reliable yield strength in stainless steel. It is often thought to be harder than mild steel and therefore stronger. The opposite is true. Hardness makes the metal more brittle and therefore unable to stretch to absorb loads without breaking.

The most common markings for stainless steel are A2 or A4, which relate to the alloy, and then 60, 70 or 80. These equate to the first digit in the mild steel series with an additional zero to denote the lack of a recordable yield strength. It must be noted that the stainless steel bolt with the highest tensile strength is equal to one of the lowest grades of high tensile mild steel bolts.

So when considering replacing mild steel keel bolts with stainless steel, remember that the designer specified the size of bolts, the number of bolts AND the grade of steel bolts in a complex calculation of loads and stresses that they will be subjected to, he wasn’t just trying to save some money.

Also, think about this. Why is it that the motor industry never uses stainless steel bolts? It is very frustrating trying to disassemble a car suspension or drive train with mild steel bolts that have been covered by years of salt or mud. Stainless steel would be so much more sensible … or would it? Think about that next time you hit a pot hole at 60mph!

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