Guitar Care

understanding how weather & climate affect your guitar

Thompson Guitars are made to withstand moderate changes in humidity and temperature. If there are prolonged changes in both humidity and temperature this may cause certain symptoms to occur and can lead to damage. It is important to care for your guitar to protect the tone, playability, and appearance for the lifetime of the guitar.

Depending on what climate you live in you may need to keep an eye on seasonal weather changes and either add to humidity levels or reduce them. In general, in the summer months excessive moisture can be a problem and in the winter too little moisture can have affects on your guitar. Your guitar will show signs of issues with this expansion and contraction of the wood. Understanding the affects of weather and humidity will help you keep your Thompson Guitar in its finest working order.

Summer Guitar Care

If the guitar absorbs too much moisture (humidity beyond 55-60%) it will expand and swell. It can weaken the glue joints and with prolonged excessive moisture, the glue under the bridge can weaken and even pull off.

The signs of a “wet” guitar are:

  • Swelling of top and back
  • High Action
  • Muffled tone quality – low volume
  • Finish Cracks
  • Binding separation

Things to consider for storing your guitar in the summer months:

  • Don’t keep your guitar in a basement during high humidity
  • Don’t keep your guitar in a truck of a car
  • Keep exposure from direct sunlight to a minimum – to avoid premature yellowing of top.

All problems that are caused by high humidity if short term should correct itself when the guitar returns to a normal range of humidity (40-45%) relative to room temperature.

Winter Guitar Care

If the guitar is in an overly dry environment with a lack of humidity (under 40%) the wood will shrink and crack.   Simple guitar humidifiers in dry regions might not be enough, so make sure you check your room humidity and keep it at 45-50%

The signs of a “dry” guitar are:

  • String buzzing – caused by low action
  • Bridge lifting
  • Finish cracks (below 30% humidity)
  • Fret lifting – causing fret ends to stick out from fingerboard
  • Dips in the top or back

Things to consider for storing your guitar in the winter months:

  • Keep your guitar in a case with a humidity device
  • Allow your guitar time in the case to warm up slowly if exposed to cold

If you start to see any of the signs above either in summer or winter take note of the humidity and where the guitar is being stored.


In the early 20’s Nitrocellulose lacquer became the preferred finish on high-quality furniture and musical instruments. It is an exceptionally fast-drying solvent finish and a stronger version of the original shellacs and varnishes and is what we use on our guitars.

Nitrocellulose lacquer can be applied in multiple coats, but the resulting finish is still thin and protective. Because of its glass-like quality, it does a superb job of showing the beauty and grain of the wood. Also because it is such a thin finish it does not inhibit the natural sound of the guitar.

Compared to the more modern day polyester finishes it can be affected by solvents, alcohol, certain acids and other substances, care should be taken to avoid prolonged exposure with any of these.

Nitrocellulose lacquer buffs to a high gloss and has a softer sheen, which may, in turn, show more wood grain compared to thicker poly finishes.

A brand new guitar with a nitrocellulose finish will be shiny and beautiful, but over time as the guitar is played the finish will begin to age – for example; swirl marks created by sitting the guitar on different surfaces or just holding it and playing it. If you are very particular about your finishes even shirt buttons and belt buckles will mare the finish, however, this creates the character of each individual guitar.

This type of finish, as it dries over time, creates a warm vintage patina something you see in guitars from the Golden Era. Sometimes because of climatic changes, you will see small finish checks or alligatoring of the thin finish, but this does not affect the integrity of the guitar or the protective nature of the finish.

The best way to care for this finish is to clean your guitar with a damp warm soft rag and/or a very quality guitar polish that does not contain silicones.

At Thompson guitars, we take pride in applying the highest quality finish to help set the stage for that vintage quality and tone.


Thompson guitars are adjusted at our shop with a medium string height. We hope that your guitar arrives without an adjustment needed, but if your playing style requires some tweaking our recommendation is to bring it to a seasoned repair person or contact us directly to see how we can help you.

You can sand the bottom of the saddle or install a new taller saddle. It can be raised or lowered depending on the style you play. Always remember that a very small amount of adjustment can change the playability or even create a buzz that wasn’t there before.

It is perfectly normal to see bellying or bulging of the top near the bridge due to the humidity. We build a certain amount of flexibility into the top to accommodate this movement.

Our necks are also adjustable using a 1/8 inch allen head wrench through the sound hole. Adjusting the neck affects the amount of relief or bow in the neck. This needs to be done very carefully and best to be completed by a guitar repair tech. Remember a small amount of adjustment can go along way.


When shipping your guitar make sure you put the guitar in a case and then a guitar box with packing material.   Take the string tension off of the strings and place a humidifier in the guitar if traveling during cold months or from a wet climate to a dry climate. If there is any movement between the body of the guitar and the case add in some crumbled newspaper in between case and guitar so it doesn’t move while in the case.


If you have any additional questions or require further advice on guitar care, please do not hesitate to contact us.

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