Stress cracks are cracks in the gel coat of a boat that let you know there is undue stress on a particular area or a problem under the gel coat. I have a 79 11ft Whaler and it is covered in cracks in the gel coat, but none seem to be wide enough to tell me there is a problem. They seem to be common on boats of that age.
...
Stress cracks on GRP boats.
| Cracks | Scratches |
|---|---|
| Go through the gelcoat | Are shallow, do not penetrate the gelcoat |
| Bottom of crack can't be seen | Bottom of the scratch can be seen |
| Sharp edges | Ragged edges |
| Can run in parallel lines | Hardly ever run in parallel lines |
What causes stress cracks in boats?
This can be the result of a high flex area enduring heavy seas or too much load on the boat. Cracks may also form at a bulkhead or other hard spots behind the fiberglass when the boat flexes, creating pressure.
What do stress cracks look like?
Thermal stress cracks in windows are easy to identify because they start perpendicular to the glass edge. “It's easy to identify a stress crack if you can see the edge of your glass,” adds Howard. “The crack will extend about a half-inch straight away from the glass edge.”
What are stress cracks?
According to ASTM D883, stress cracking is defined as "an external or internal crack in a plastic caused by tensile stresses less than its short-term mechanical strength". This type of cracking typically involves brittle cracking, with little or no ductile drawing of the material from its adjacent failure surfaces.
Are spider cracks normal in boats?
Spider cracks are non-structural damage to the gel-coat of a boat. This damage is often caused by slight flexing of the hull. These hairline fractures also occur in boats of the mid 1970's vintage which often had thicker gel-coat layers than newer boats.
How do you fix gel crack stress fractures?
In order to properly fix any spider cracks, you will have to open the cracks to fill them up correctly. This can be done by using a Dremel. Once the crack is open and it has a good size you can sand and clean the area. For cleaning, you may use acetone or soap and water.
How do you cover settling cracks?
0:141:12How to Fix Cracks in Drywall - Sherwin-Williams - YouTubeYouTubeStart of suggested clipEnd of suggested clipPaper access spackling onto the surrounding wall then let it dry. Completely. That's very importantMorePaper access spackling onto the surrounding wall then let it dry. Completely. That's very important smooth the surface with a fine grit sanding sponge and wipe off the dust with a tack cloth.
Does insurance cover stress cracked windshield?
Does Car Insurance Cover a Cracked Windshield? Yes, With Comprehensive. Even if it's a tiny crack, you need to get it fixed: they rarely stay small. The good news is that any comprehensive policy should cover auto glass repair or even windshield replacement, as long as the crack was from a covered event.
Does insurance cover stress cracks in windshield?
For the most part, insurance companies will cover the cost of windshield repairs so long as the damage is a small chip or crack. More severe cracks and breaks require the windshield to be replaced as a whole; something insurance companies try to avoid whenever possible.
How do you fix structural cracks?
Because of the risks they pose to your home and loved ones, structural cracks should be fixed by a competent foundation repair contractor as soon as possible. The most common method of repairing them is installing carbon fiber strips or reinforcing steel beams to the damaged walls.
Can a spider crack be repaired?
Generally speaking, chips smaller than a quarter and cracks up to three inches long can be easily repaired. If the spider crack is smaller than 12 inches long, we can repair your windshield. How deep is it? Think of a windshield like a glass sandwich.
How do you fix spider cracks in a boat?
Repairing Spider CracksMove your boat to a safe workplace. First, get your boat to a well-ventilated area where it can be sheltered overnight.Clean the area. Clean the crack area with acetone. ... Sand down the area. ... Remove sanding dust. ... Tape off and apply gel coat. ... Dry, sand, clean and paint.
What causes spider cracks in gelcoat?
Spider cracks can indicate impact damage or serious structural problems that will need to be addressed to prevent spreading, but most often they result from relatively inflexible gelcoat that is too thick. Stress by thermal expansion or when bulkheads and liners were installed can cause minor flexing.
What causes stress cracks in walls?
A main cause that'll have you fixing stress cracks in drywall is your house settling. It's normal and happens with all houses. As homes age the ground under them can shift or settle especially with changes in the weather. These slight changes can create stress on your home which results in these small cracks.
What are the different types of cracks?
The most common types of cracks are organised in the following 7 groups Plastic Settlement. Plastic Shrinkage. Early Thermal Contraction. Long-term Drying Shrinkage. Crazing. Corrosion of Reinforcement. Alkali-aggregate Reaction.
What causes stress cracks in concrete?
As the slab loses moisture while curing it gets a bit smaller. Because concrete is a very rigid material, this shrinking creates stress on the concrete slab. As the concrete shrinks, it drags across its granular subbase. This impediment to its free movement creates stress that can literally pull the slab apart.
What causes stress cracks in car paint?
Paint cracking can be caused by another of factors, including poor flash time between coats, force drying of undercoats (or excessively thick ones), improper paint mixture, excessive hardener use, and exposure to extreme temperatures or moisture.
What is stress crack on a boat?
Excerpt. Stress cracks are a commonly occurring phenomenon with reinforced plastic boats. A lot of boat owners get very upset when they see these cracks, sometimes needlessly, while at other times their fears are well founded. Clients will often ask about cracks and the surveyor will be expected to provide answers.
Why is my boat's hull cracking?
When it comes to large, flat panels, cracking usually results from excessive panel flexing or panting, such as on an unsupported hull side.
What are some examples of stress cracks?
A good example is a strut attachment to the bottom without any kind of doubler. Another example would be a bottom stringer butting hard against the laminate with no fillet to distribute the load. Yet another is a railing stanchion attached to a deck laminate with no fillet or doubler beneath. The end result is that the amount of stress suddenly rises at a certain point and so stress cracks are likely to appear.
Why does gel coat crack?
The primary reason why stress cracks appear in gel coat is because gel coat is brittle and the laminate to which it is bonded is less so. Gel coat is basically a resin to which a large amount of coloring pigment has been added, pigments that are oxides of metals like aluminum.
Why does my sandpaper crack?
By far, the most common reason for stress cracking is due to improper structure design .
Where does stress riser occur?
A stress riser occurs at point in a panel or hull skin where a normally somewhat flexible area is suddenly made rigid without a means of transferring the imposed stress gradually to the rest of the laminate. A good example is a strut attachment to the bottom without any kind of doubler.
Can a surveyor find no basis for cracks?
There are often times when the surveyor can find no basis or cause for their existence, and thus it is left without an explanation to give. It will be useful to have an understanding of how and why these cracks commonly occur.
What are stress cracks on a boat?
Re: Stress Cracks#N#Stress cracks are cracks in the gel coat of a boat that let you know there is undue stress on a particular area or a problem under the gel coat. I have a 79 11ft Whaler and it is covered in cracks in the gel coat, but none seem to be wide enough to tell me there is a problem. They seem to be common on boats of that age. If it looks like the transom is about to fall off stay away, but if not, I'll bet you will have a hard time finding a boat with none.
What does it mean when an owner calls a stress crack?
Re: Stress Cracks. If an owner calls cracks, stress crack, he is letting you know there is a problem. Where is the stress crack is important, but unless you are 1) a skilled boat surveyor or 2) the boat is cheap and you are not going to cause more stress, stay away. It takes a lot to break a whaler.
Is fiberglass hard to repair?
Welcome to iboats. Fiberglass is not hard to repair, but the term "stress crack" must be followed but what type of stress crack and how big an area. Pic are always good.
What are the cracks in fiberglass boats?
Hairline cracks, stress cracks or spider cracks (star cracks) that occur in gelcoat surfaces on fiberglass boats or other water craft are often seen as a cosmetic issue. In most cases this is true, however it is important to seal them correctly otherwise water may penetrate into the fiberglass and cause more serious damage.
What causes radial cracks in boat?
Radial cracks (spider cracks, star cracks) – caused by impact or by a fixture / bolt that puts strain on a certain area of a boat and cracks occur around the hole. Thermal fatigue cracks – when gelcoat repeatedly expands or contracts. These might be in a parallel pattern or a non-directional pattern.
Why do resin cracks get bigger?
The main causes are: Swelling of the resin due to water diffusion. Wave action and rigging stresses.
How to avoid spider cracks in fiberglass?
Spider cracks can be avoided by countersinking holes just through the gelcoat, so the load is placed on the structural fiberglass rather than the brittle gelcoat. There’s also a great article on how to drill holes correctly to avoid chipping and cracking in fiberglass.
Why are fiberglass boats cracking?
These problems occur as a result of: Manufacturing defects. Environmental challenges. Stress and movement. Also, older fiberglass boats tend to have a thicker application of gelcoat which means they are more susceptible to cracking. Stress cracks first appear as very fine hairline cracks.
Can you repair stress cracks on fiberglass?
Most stress cracks occur in the gelcoat layer of fiberglass surfaces and can be repaired by yourself. If structural damage is suspected, you should get your boat inspected by a qualified boat repairer. These problems occur as a result of:
How to clean cracks in fiberglass?
Once all the cracks have been ground away with the Dremel, re-sand the area with the sandpaper to smooth out any rough edges or burrs. Wipe away all of the sanding dust and ground fiberglass bits, then wipe down the entire area with the rag dipped in solvent again. It's very important at this stage to ensure that the surface is completely clean and uncontaminated.
What is gelcoat cracking?
Gelcoat Repair on Boats. Crazing in gelcoat, also known as spider cracks or stress cracks, plagues countless boaters. Here's how to fix the problem. Crazing is an incredibly common issue on modern fiberglass boats, and although it usually starts off as a matter of cosmetics, in severe cases these surface cracks can grow, deepen, ...
How to fix a crack in a dremel?
Fit your Dremel with a silicon carbide or tungsten carbide bit, in a bullet or cone shape. Using the highest speed possible (bits turning at lower speeds tend to grab and rip the gelcoat, causing chips and splinters instead of a smoothly ground surface), start at one end of each remaining crack and grind all the way to its other end. You'll need to grind down through the crack until you've exposed uncracked gelcoat or fiberglass beneath the surface, but don't try to rush this part of the job; let the bit and its speed do the work, as opposed to applying a lot of pressure. It's usually best to run the Dremel along each crack lightly then go back and do it again, as opposed to trying to grind deeply on the first pass.
How wide should a crack be?
A surface area at least a quarter-of-an-inch wide (including the crack itself) will need to be sanded with medium-grit sandpaper. If you're dealing with a few long cracks that are separated by an inch or more, you can sand each one individually; otherwise sand the entire area of cracking.
How to fix crazing on a wall?
Before you can start to fix crazing, clear the area of any obstructions and remove all hardware that covers or obscures any part of the cracks. Then, get busy cleaning. Thoroughly wash and dry the area, and remove all obvious surface contaminants with a rag dipped in a strong solvent like acetone.
How to remove gelcoat from fiberglass?
Sand the fiberglass down until there's no shine left, so you know the gelcoat's surface has been removed. In the case of very fresh, shallow crazing, sanding alone may remove some or all of the cracks.